it is not the same.
apple is not the owner of apps you make, they only distribute it. Imagine the world where a news paper distributor(news-stand) would limit the type of ads you run on your newspaper.
Wal-Mart, for instance, may sell newspapers, but they're well within their rights to not sell newspapers with, say, pornographic advertising.
it would be the same if wallmart said, all newspaper advertisements must come through me.