But Apple is in the business of selling and streaming music, so actually they have a point.
I'm not a Spotify user and I don't care if that 30% goes to Apple or Spotify, but it is clear to me that a company owning a platform and selling music is both a supplier and a competitor for Spotify, so it is obvious Apple has a big advantage over them on iOS.
Same for Netflix, Apple is selling content via iTunes and will soon have its streaming service so it will be in the same position.
Let me tell you what is not good for the users, which I care about. Having to pay more on your iOS device, or be forced to go to the company's site to pay for a subscription is bad user experience.
Apple deserves a cut, and 30% is ok for a small company or an indie developer. I make apps, and I'm ok with paying a fee to Apple or Google to be on their stores. But me and my company, we are "nobody".
Netflix, Amazon, Microsoft, and even Spotify don't need Apple to promote themselves, they take advantage of Apple's platform, but on the other end users expect those services to be on their devices. Netflix can't take its app out of the store, and Apple can't ban them either. So that's what is going to happen, they'll reach a deal with those companies and let them pay less than 30 or 15% for subscriptions, and everyone will be happy before a judge or some European Parliament will intervene. It is in their best interests. I'm tired of lawsuits and I think having only one store is better for the users, so I'm ok with the status quo. I live in EU and knowing how the commission thinks about those matters I think Spotify have a case here, maybe not in the US, but I'm sure Spotify have good chances here. Microsoft was fined by the European Commission, and the same could happen to Apple.