I think it points to something more going on or happening to the motor - some sort of abuse whether in the form of riding style or lack of/improper maintenance.
I've run both my '04 and the last '09 hard down in the W. NC / E. TN mountains and never had the temp gauge move above the normal range (upper end, maybe, but no where high enough to cause concern). "Hard" in my book is rev - limiter range. Especially on that stretch of NC 28 from CROT through Fontana to the four lane section, then hard again between 74 and Franklin.
The only time I had the motor get noticeably hot was during summer MSF classes in South Carolina. I left it at idle for some time while I changed over range cones and when I got back on the temp gauge was elevated, fans running, but it didn't overheat.
Hmmm... only revving to 6k should not overheat the old girl. But if I stayed in 2nd gear down the CherryCola I know I'd be well over 6k. It's pretty sweepery in a lot of sections. Maybe you were holding it just a tad higher?