Except that exactly this approach is going to make Apple more successful if Apple apps are the only ones allowed to have uncompromised UX.
One major difference is that iOS enjoys an advantage in apps that Mac never had in software. I think that could change, though. There is a positive feedback loop in which the most popular platform attracts developers and hence has the most software and so people buy that platform. I don't perceive that system to be in a stable state at the moment, much like it wasn't in, say, '88. People routinely develop for both platforms. And who knows, perhaps that will be the steady state answer this time; we're a lot better at abstraction than we used to be. But I think it's possible that Android could become popular enough (and perhaps Apple drive enough developers away), that the whole thing could pass a tipping point.
What I'm saying is, I don't think the beauty of the apps is the most powerful force in play here. I think the existence of apps is a lot more powerful. At least, that's what I think happened last time beauty fought pragmatism.
With iOS vs. Android, from the consumer's perspective, the differences are really subtle. The major issue at hand with developer freedom is hidden from view for most people.