I think that because Liszt earned the title of a priest (not an easy task, usually)…says a lot about how he felt but never told anyone, maybe about his mistakes in life, the ungodly passion he showed, the desire in him…I also think his music reflects that, not necessarily in a very obvious way. But I think that the harmonies he writes, they are the sound of his heart. I think there was a lot of sadness in him. The complex piano stylings and technical challenges he presents in his music is just his character, and not for the sake of virtuosity. I think that he was never happy with him self, so he wrote all these grandiose, overwhelming pieces. And the actual music (not the technical barrier he created UNPURPOSE, but not for virtuosity) is what is really touching. But you have to understand why that technical barrier is there, and it is not simply because Liszt was a show off. There is a personal reason behind what Liszt was and what he did.
As far as Chopin, I would see him as someone who many can understand, unlike Liszt. Chopin was someone who was (obviously) highly capable, but suffered from a lot of anxiety and stress. Otherwise, Chopin was a pretty normal person. And it was likely people died from disease, where cure did not exist yet. A lot of people can appeal to Chopin's character. He did have a serious career in music, but his music was the most prominent thing about his life. Where Liszt had so much more time to live a much more passionate life.
This still does not mean I think Liszt's music is more beautiful. It isn't. But I do not agree when people dismiss Liszt to be all about virtuosity, when virtuosity had been dismissed from performance, centuries ago. Virtuosity is just a part of the 19th century composer package. If difficulty makes it difficult to find the music, then you have quite a journey to make, to discover music.
Difficulty is only overwhelming if you do not see a solution. The solution is there, in the music that Liszt wrote.