Mozart's music was considered too edgy and quirky in his day, actually. People who were knowledgeable about music tended to like it a lot because they could follow all the twists and turns, but Salieri was the more popular composer with the mass public. The story with Beethoven is not very different, ultimately some of the simplest pieces of his were the most popular and he wasn't very happy about that.
> The story with Beethoven is not very different, ultimately some of the simplest pieces of his were the most popular and he wasn't very happy about that.
I'm sure many artists fall into the trap of 'the public likes the work I like least'. That doesn't make the work not part of the authors creation. For example, Raffi makes extremely popular (and actually pretty good) music and I'm sure he absolutely hates having to play it over and over again. Still a better artist than Schoenberg.
We forget that although there are many surviving transcripts of their work, Mozart and Beethoven also improvised and performed on stage a lot. That whole genre of classical music is lost.