So here's an opinion: I'm a better than composer than any composer mentioned in this thread.
Do you think that's a valid opinion, considering I've never written anything?
Of course it's not, it's stupid, because opinions can very well be stupid. Just like yours is.
If it IS your opinion, then yes, it's valid.
Only because it IS...yours. Not because it's true or not.
Mine is stupid to you, because you don't understand my reasoning, which is purely my fault.
All opinions are valid, as long as they're believed by at least one person. I believe God is dead. My opinion is valid, although some would say not true.
Reasons why Mozart sucks at piano music:
1) As compared to Haydn and Handel and the Early Beethoven (which I don't like either), he simply OVERplays the era's style, like the Baroque (as in too much) version of Classical music, if you will.
2)He gets stuck on themes. They show up OVER and OVER and OVER and OVER, he just changes a note here and there so he can say it isn't the same.
3) As an orchestral composer, he just lacks the ability to give his piano music the oomph that he gives his orchestral music.
I don't hate Mozart, I hate his piano music, and even that opinion has exceptions.