The thing is, Netflix now is very different from Netflix 5 years ago -- most of the content is the one they produce. Music doesn't work this way, many people just want to listen to old music while it's rare for people to rewatch old shows and movies. There are many albums I have listened to tens of times, and I don't think I have ever watched a film more than three or four times. If the labels pull the artists to make their own Spotifies, Spotify will be left with pretty much nothing, in a situation much worse than Netflix