Apple's market is one of their own making, and is in fact something of a submarket. They control the platform, period, and when you agree to the terms of their developer agreement, you agree to be bound by them, so you are subject to the same rules as everybody else. They don't have any market monopolized, they merely have their corner of the market locked down.

and they aren't locking in any body. You don't forfeit rights to your source code, you're welcome to write some crossplatform app using some shared code library you build in-house. You just have to build apps natively, rather than use some watered down piss poor Common language that breaks standards on all platforms. This is the same reason adobe apps suck on macs. They have tried to abstract away the os from their applications to the point where they don't look, act, or function properly on any platform. They look like ass and run like ass on everything .