Man, a lot of people here don't understand how the music industry works. From the perspective of someone who's been loosely following the music industry, what I've learned is that it doesn't matter if Spotify gave up 2/3rds of their revenue, or 100% of it, the artists would still make fuck all.
Why?
The labels love taking their cuts and as a result, artists make very little. Instead of taking the blame for giving artists a <10% cut of the label's revenue from their music (my understanding is that it's pretty common for musicians to get <10%, sometimes <5% if you're on a particularly shitty label), the labels are blaming platforms like Spotify.
Now, I'm not saying that Spotify is blameless, however I think there's a lot of misdirection from the labels going on. I don't remember anyone complaining about pre-spotify services like Pandora Radio for not paying out enough when they were largely ad-supported, which is another reason I'm not totally buying the, "it's cause it's free" argument either.
Fuck, remember Pandora?