Not all monarchies are bad, but most eventually turn worse. That's where the comparison to the iPhone platform is relevant. Apple has a lot of control over the platform, and so far people haven't been overly concerned about that. But over time people may start to realize that Apple is not as benevolent a company as they've been led to believe.

Yes, people can go elsewhere. And I think that's precisely what will happen. Apple has had the lead in mobile app development as a platform up until now, but their restrictive and short-sighted rules and policies may very well sap much of that momentum.