I would not call iOS 4 on the iPhone 3G "robust": it was more of a disaster than anything. There are obviously strengths to all sides here, and I don't mean to champion that Google's is best or the only way. But I think it's clear what they're doing, and I'd bet they've weighed all possible options and found this to be the most economically sensible one.
I honestly thought Apple's behaviour with the 3G was shameful. I wouldn't have minded if they hadn't released the update for the 3G, but instead what they effectively did was brick a load of people's phones and then offer poor options for downgrading. It's really not what I expect from a premium brand.
