But every app developer who has a subscription model for their iOS app already has this in place. And they can do it for a 3% fee from PayPal, where is the other 27% of value?

Ask the guy who made a million dollars off Pixelmator in the first week because his was the featured app on the Mac App Store

That's an app with a one off payment, we're talking subscriptions here. The point being, do you get that 30% (ok 27%) value from Apple when they take it every month. Also, note that I'm not saying I disagree with Apple taking a cut of subscription fees, I just think 30% is insanely high, it should be around 5%. Also, I don't think it should be mandatory.