Indeed, two years ago I — a long time iTunes user — abandoned it because (1) it was too unreliable, and (2) it had become too bloated, taking too long to load.
The final straw with reliability was when they linked iTunes to Safari: I deleted all my cookies in Safari, only to then discover with dismay that doing so irreparably messed up iTunes. Even Apple Support was not able to truly fix the damage that this caused to my iTunes library.
And a music app that takes more than ten seconds to load is a non-starter. There is no reason why one’s library can’t pop up instantly in a sidebar on the desktop, and clicking on a song should start playing the song instantly. Having to wait 20 seconds for the iTunes pig to come up kills the joy.