If Spotify wasn't on iOS I would move back to Android in an instant. I don't like Apple services because I don't want vendor lock in.

I use Spotify because they're independent and support a large number of devices. This is just like how I use Sonos because they're independent and support a large number of services.

Apple benefits greatly from having high quality, third party applications on iOS. Wasn't the lack of third party apps/support one of the big issues with Windows Phone?