My guess is that the problem is that many people expect GT kids to be better at it than they are. Something of the "If you're so smart, why can't you remember your lunchbox" kind of thinking. But 8yos often forget their lunchboxes.
I do agree that I don't think GT kids are worse than kids that are not identified as GT. Kids will be kids, but I do think that it is more noticeable at times. Almost daily when I see my son do something stupid I have a thought in my head that goes a little something like this "why in the world would you ever do something like that? Oh yeah, you are 4 that's why"