It's also just that Android is an immature platform. Apple has no way of enforcing its UX guildelines on OS X apps, but yet most applications are at least pretty close. (well, mostly)
I think that is a fair reason for the current state of Mac applications, as theirs is a cultured built over many years between a relatively small number of people. But the iPhone has brought a hoard of developers who are new to the platform, so I find it hard to believe that a real, distinct culture has formed yet when compared to Android developers.
