Interesting you did not mention Windows Mobile. It is not healthy to have the OS maker deciding what application can or cannot be distributed for its OS.
I mean, the difference is staggering: Apple gets cussed out daily because of how closed their iPhone app distribution system is — but nobody is wasting a single breath about Microsoft's Xbox equivalent.
I'm going to go out on a limb and say that it's just because were used to one, and not the other.