Sure, "because I have preferences which changing the world would more effectively maximize than leaving it as it is" is more accurate than "because I can". And, sure, maybe an arbitrary superintelligence would have no such preferences, but I'm not confident of that.
(Nope, it's standard (locally).)
I wrote a blog post responding to Kevin Kelly that I'm fairly happy about. It summarizes some of the reasons why I figure that superintelligence is likely to be a fairly big deal. If you read it, please post your comments here.