I'm sure many developers find Objective-C/Cocoa/Xcode to be a terrible development environment, but they do it anyway, because that's where the action is.
I don't think many people have the type of religious aversion to Windows or non-Apple platforms that Marco is alluding to.
(Also, are there really any high-profile iOS apps remaining that aren't already available on Android because the developer refuses to write software for Android? Instapaper and Flipboard were the biggest I could think of and it's not true for those 2 anymore)