Yes, that's mostly true. Apple had already some software running that could be ported over to iOS, and many Android apps started out being designed for small screen phones, so there's a natural lag. I would hope that Google is fast tracking some things like print drivers and porting some open source programs like AbiWord over to Android as fast as they can.
Although there is certainly no reason that Android can't do everything iOS does, my point is simply that's it's not quite there, yet. As Android catches up, I expect it will cut into more of Apple's sales. Until then, people will choose the platform that has the capabilities they need already working.