The first is that your claim about Android underperforming iOS doesn't seem to have any merit. I have a Lollipop device here and it's as smooth as any iPhone I've ever used.
I nearly went into this with my post, but decided it was better to make a simple clear point without dealing with the obvious avenues for counter-argument in advance.
Android got smooth by throwing hardware at it. The reason for a while Androiders were bragging that their phones had more cores or higher clock speeds was that Android needed it.
Then there was the NDK, whose justification was explicitly things for which Java and Garbage Collection were unsuitable.
I don't know anyone who thinks C++ isn't a systems language. For the simple reason that C++ is C when you want it to be. Such people may exist, on the internet there are all views represented. But they don't know what they are talking about if so.
And I don't really care who's behind the language. And I certainly wouldn't any extra weight to an idea just because some people at Google think it.