PC is a farrrrrrrrrrrrrrrrrrrr larger world than the bubble in which we Mac people play. Pay attention and you'll see DOS apps still running in relatively important settings- like hospitals. DOS! I just bumped into it in dominant use with a not-poor client only 3 years ago.
I would wild guess- and it is just that as I have no data to support it- there is more-to-far-more active iTunes users than Mac owners.
Here's a surprising(?)
PCmag quote from only 4 years ago...
I clicked
a link into the store to see where it ranks now. It's #2, right behind WhatsApp and
still ahead of Netflix and Spotify.