As an app developer, what bothers me is not so much the fact that you have to pay the 30% when going through the app store it's the fact that you cannot even mention the Android Play store AT ALL. Also I don't like that they completely force app developers to use IAP instead of supporting other purchasing flows (without Apple's cut)
Pre-smartphone era pretty much every hardware vendor didnt impose arbitrary restrictions on software like that (the notable exception being video game consoles). If you wanted to write a Mac app that said "also available on Windows" (or vice versa), no one cared.
