Basically two things happened to cancel it:
1 - I have an awful time deciding what I want to do/play/listen to when it's completely wide open. It's ruined term papers. There's a reason I go for discography runs and go through HAULs alphabetically until I've had my fill.
2 - On the Android app I could pick a particular song, but it went to radio mode after it got done streaming. The app without the subscription was basically broken; upon learning that the desktop version was just like the premium version but with ads, I got pissed off and cancelled the subscription. I wasn't using it, anyway.
The other reasons have been covered.