I'm not an Apple fan and I've pretty much avoided their ecosystem. I'm not a fan of walled gardens but I can recognize why some people will be fine with the arrangement.
With that said, Apple builds the handset, the OS and the store. It's all their proprietary stuff, obviously sitting on top of BSD (still legal). Given they have no monopoly on cellphones, I don't really see why they can't set their market place fee to what they want. If a developer doesn't want to pay the price, they can go make an app for someone else. Apple doesn't owe anyone access to their ecosystem.
It's not like you must have an Iphone to get work done. Android is a huge ecosystem with the same stuff.
Someone feel free to break it down to me why Apple can't set it's own price policies.