Honest question: how/why is it legal for Apple to ban any other "app store" from existing? I understand the motivation to require the presence of an intermediary to combat malicious software, but it seems blatantly anti-competitive to forbid competition within the domain of providing this intermediation service.

Similarly, why haven't any major app companies challenged Apple on the 30% app store charge, and how it is inconsistently enforced? For example, rdio charges a premium if you purchase a subscription through the app store, but MLB radio does not.

I don't know much about these things, but as a user I think it's fair to conclude that Apple has not done a very good job of app store stewardship, and I personally would welcome potential new overlords.