Yes, performance. And I never doubted that it supports C++, but the point is that it also officially supports C# which, if it can't be JITted, will take a nasty hit. iOS has no equivalent to C#, since the only officially supported languages are compiled ahead of time.
I'd actually say this is most likely. You get a hit on install times but after that startup times get much better. Getting fast app launch times are incredibly important.
