Bingo. Apple doesn't ever want to find itself in a position where it has to depend on 3rd party tools keeping up with its OS evolution. If/when Android ends up being the dominant mobile platform, every dev house will likely make a "business decision" to use cross-platform tools. The control point for app innovation would then be in third party hands.
And as for losing out on innovation because developers can't make their own tools, I'm sure Apple isn't worried about that at all. They seem to have enough in-house innovation to run circles around what the competition has to offer, for the past ten years.