Actually I thought this problem was typically Swedish, or rather "typically Scandinavian".
I wrote a blog post about it, https://pianovning.wordpress.com/2016/11/23/ow-wouldnt-it-be-loverly/
I had a read through your blog and found these parts near the end very interesting:
[In Sweden, the elite of today normally only educates the elite of tomorrow. They don’t have time for anything else. You must not join a master class if you are above a certain age, or if you don’t have got enough grades from a conservatory and so on. This is due to our educational system which is free, and very fair in many aspects, but it certainly is of no favour to middle-aged hobbyists who are in the desperate need of an inspirational kick just to get up from the couch again.]
[Yet, now one of our most prominent pianist stars, my big piano idol as well, offered to give lessons to a person like me …
…but you know what the typical Swedish reaction to such a non-typical Swedish offer is?
“Ha ha, that would have been fun, too bad I am not good enough, though. I’ll pass.”]
This forms in my mind a very pyramid type world of education where at the top the training is kept secret and only for those worthy, it is unfortunately a reality all over the world I think. This is wrong to me because I feel music only lives on and improves through the "normal" people in this world who love and appreciate it, not the microscopic amount of artists who produce the music. I am so glad when my students teach their own brothers, sisters, parents, friends, family the piano in the way I have trained them, the knowledge is shared!
This is education in my mind, how to become more disciplined and work in a more efficient way within a particular subject. Discipline is something generally not taught at a university no matter how prestigious, you either sink or swim. Goal setting, dealing with failure and success, aspiring etc these type of experiences all are left to the students to have almost in total isolation. This to me is not education. If you set a test and a student fails you kick them out of the school and they are left to feel a failure. Ridiculous, a failure on the schools behalf. There should be no such thing as failure when a school accepts a student, there should be 0% drop out because the student didn't jump through the academic hoop appropriately. Why can't these great schools deal with individual students failure, pinpoint the causes and assist them every week? They don't do this. In many universities where it is not free they will happily take tens of thousands of dollars from you, sometimes even hundreds of thousands, but what service do they really give you? They merely hold this golden hoop of a degree that you need to jump through but they have no interest in helping a failing student achieve this. If you can't do it you are a failure and you get nothing. This is not education although it is been like this for hundreds of years. Instead I believe a student should stay with the school as long as they need to until they themselves realize they can't do it. Sometimes people need that extra time and then they shine, I have seen it so often in my own teaching experience but in our harsh world if you don't do it within a specific time isolated from your individualism, you are a failure.
In Sweden, we certainly measure the student after his/her teacher.
Yeah i think this is a knee jerk reaction many non musicians have! I have parents thanking me for how well their children are going but I always point out how well their child is working on their own and that their assistance to help their child own practice is invaluable. But what about students who have no guardians to support and motivate them, my adult students often have no one there to push them when they are on their own and when they do well it really is because of them not me. Yes I give them direction and how to practice but if they don't have the motivation to do it themselves it can't work. I warn my students always how easy it is to think about what to do and know how to do it, but then to go and do it that is a totally different matter which tests everyone. To me this is where the biggest compliment to someones ability rests, how they have motivated themselves to do the work, to want to do it, to have reason to do it, discipline.
I guess you can think of this metaphorically in terms of trains and tracks lol. The train themselves represents a students discipline towards work and the tracks are merely the musical teaching I lay out for them. Oh look at those rusty slow trains hardly moving, I shall oil the parts, remove the rust, give the engine a kick, try to get this broken down thing moving since it is not doing well on this track (even if it's a downhill one!). Oh look at this amazing modern bullet train! My goodness you fly through many of the tracks I set before you but I am sure I can find improvements to your engine and show you tracks that will challenge you. It is stupid to compliment the track if the train itself is a bullet! Of course both are important I am however more drawn to improving the trains no matter what condition any idiot can lay tracks down and not care if the train goes over it effectively or not.
Why are some students lazy, lack motivation and seem "untalented" in general? Well, most likely some are just lazy, lack motivation and are untalented in general. Piano playing cannot be everyone's cup of tea, and you are definitely allowed to try a hobby out and then conclude you lost your interest in it. That is normal, that is human, we all do it and it is perfectly ok.
It is often how they have been brought up, the parents or guardians are key figures which dictate how disciplined a child is towards work. This has far reaching effects through into the child adult life. Some families really make knowledge taste wonderful, they support their children in their effort to work hard, motivate them, reward them, hold their heads up during failures. Not everyone has had such support in their childhood, some have had less than desirable starts to life! But everyone can improve, it is never too late, it is hard to awaken the dead beaten down heart but you can start a spark and nurture it.
Most of my students stay with me for years because I really teach them about the discipline it takes to do music successfully and help them no matter if they succeed or fail at it. Those who resist it completely all lose interest very fast. Some have an idea that playing piano is impressive and amazing but then when they are faced with the work that actually goes behind it all, that rose tinted glass shatters.
I find most people become more disciplined when learning piano is no longer a solo effort. When they can share the experience with someone else. It is why having a teacher can be so important to many students. I still have a few students who really don't need me anymore but need me because they want someone to answer to. Without me they feel they would flounder about. This is important to realize, not everyone can work on their own as well as if they had a musical buddy to work with.
Discipline can be trained on many many levels and over the short and long term so there is zero excuse for anyone to not start improving as it is a concern to all improvement in life. Adults are often stuck in their own routine of living the and can be resistant to make changes to themselves until they are forced to. Too many adults think about it, just think think think and never do because things are not urgent enough. They make so many first steps only to give up because the urgency of what they are doing is not enough to stay on track with.
The same goes for so many issues in life, issues with health for example all requires self discipline but people often only do something about it when things come to a critical point. For example when you develop diabetes because you are morbidly obese so you start thinking about losing weight. Why can't we find motivation before things become an emergency situation? You certainly will find it very difficult to create emergency situations to make students to want to learn the piano

Exam deadlines, concerts, competitions all do motivate people to work hard but there really needs to be a strong source of self motivation also. Scaring people to work is not really the best way to make disciplined though unfortunately it is where many people learn about it.
But I also bet many just feel locked out. It is pretty strong to maintain an interest although voices both from within and from the outside constantly whisper to you that you are too old, you are probably not good enough, you are stupid to take this too seriously, you don't really belong here and so on, so on. This little voice from within is often so subtle that we are not aware of it, but yet we react on it - with hesitation, "laziness" and other maneouvres to mark that we are not investing too much in this, therefore we should not be scorned if we fail. You can call it a defense mechanism.
Yes it is a wrong source of motivation when you listen to other people who have no interest in your own improvement. Those who are excited for you will encourage you and excite you even further! Music is an amazing relationship that can exist on so many levels, you don't need to be an expert pianist to experience the wave of emotions you get from playing the piano, certainly not!! A beginner student of mine was brought to tears playing a simple melody because it reminded her of her grandmother, that is as powerful as anything that exists in music. Music is special, it is your friend it is your foe, you really have a relationship with it, it is not always good it can be extremely challenging but overall it is rewarding and brings you peace, it allows you to express yourself, it allows you to take your mind away from this sometimes terrible world, you can revive memories from the past and feel things you can't when speaking, you can exist within a secret safe world, you can be alone but still have company.
I therefore think it is important that teachers learn to see beyond these obstacles and that even the "untalented" and "bad" piano students can feel welcome in a serious piano community. And what is that? Teachers and others that have a serious passion for their instrument, who think it is far more important to enjoy the ride and to share the joy than to pass exams, participate in recitals, practice diligenty, reach certain goals etcetera. The love for piano should be a means to find kindred spirits, listen to wonderful music, have fun together or have fun when you are alone, and it should not matter if you are an established concert pianist, an upcoming star, or just a dabbling beginner.
We must stop the sad development where piano playing is a spectator sport, where only the Gifted and Talented are allowed to take an active part, and the rest are supposed to act as audience and often also sponsors ...
Wonderful I totally agree!!!!