I am curious if you have tried to learn a musical instrument or learn to sing? Learning to play a musical instrument (or sing) at a level were someone would want to pay you, is probably equally hard, if not harder.
But I take your point. With that analogy one can probably find an "app maker" that similarly is just drag & drop for some basic CRUD app. Just not sure that anyone actually makes those and tries to publish them to commercial repositories whereas I did get a lot of mp3s sent via MSN because half my friends were making music, and honestly many of those tracks were hard to distinguish from what I'd expect from a professional. Nowadays there wouldn't be much stopping them from signing up for a random music site account and uploading the songs there.
And yes I did learn to play an actual instrument, I know it's shit^W painfully slow (that's why I stopped taking lessons).
There is tons of info online about music theory and such but if you follow it literally you end up with something quite uninteresting.
I recently took up drawing after quitting music and found it somewhat easier. I guess it makes more sense to my brain when the target is "Replicate what you see with your eyes but with a pencil" instead of trying to understand the complexities of why music sounds good.