These comments about "greed" are pretty strange.
Apple fans are usually the first to defend the right to premium pricing whenever someone criticizes the company for their jawdropping margins. No matter if it's mass manufactured in China or uses older/cheaper components than the competition, it's still "hey, it's Apple, they're worth it, so there".
Well, Adele is the Apple of artists right now. Applying the above line of reasoning, she's worth it and has the right to ask for a bit more than the Samsungs, Microsofts and HTCs of musical artists do. Ergo she shouldn't have to settle for fractional nickels and dimes from streaming services. You certainly don't have to fear that she'll end up a billionaire like Tim Cook. She'll make millions, sure. So what?
I find this love-hate-relationship with music and the people who make it rather puzzling. A whole lot of people claim that they "can't live" without music, that it's massively important to them, second only to family, food and shelter. And yet, few things provoke them more than artists wanting to make good money. Music should be free, like oxygen. But the companies that make the hardware (that would be worthless without music), now those guys deserve the world!
"Beats headphones for $300? TAKE MY MONEY PLEASE! What, you want $10 for a music album? You unbelievably greedy swine. I bet you'd kill homeless people for a few cents, you subhuman vermin. You're a bottomless pit of unspeakable evil. Great album though!"