Well, I don't know if I can let that go without adding my two cents
The Classical period (where we find W A Mozart) was in art, architecture and music a departure from the fluff and decoration of the Baroque period and in essence a retro celebration of Western tradition. So simplicity was the ideal, not in the sense of easy but more like perfection. Newtonian physics showed the order to the universe and that was the principle which underpinned the style.
So it's true to say Mozart represented the apex of his craft within that style. He was minimal in the sense that any unnecessary notes, structure or decoration were gilding the lily of otherwise "perfect" music. He was generic both in that he adhered to the style of the time but also that he is the gold standard by which other composers of the time are measured (even Haydn who came first).
As to why he had so many compositions, whether his style is to one's taste or not, it is not because his music was just very basic and he churned it out like some hack. He was simply a genius who had enormous creative drive.
He loved improvisation and dirty jokes and in modern times I think he would have been just as amazing as a giant of jazz.
The tragedy of his short life is that, unlike Beethoven, he didn't get to move with the times and write Romantic work.
So by all means, if he's not you're thing that's fine, but chances are what you really mean is you don't like the classical period and if you do like some other work from the same era chances are the lack of ability of the composer is what create the "imperfection" which is what appeals. After all the counter-culture of Romanticism is basically a cry of "hey this perfection isn't as good as it's cracked up to be!".
A friend of mine who hates Mozart puts it this way: "I don't like neat music and Mozart was the neatest composer of all time"
Anyway here's one of Mozart's works where he uses his neatness for an entirely dirty result
https://www.youtube.com/watch?v=C78HBp-Youk