Speaking of rotary induction.......

In this months issue of Motocross Action they are featuring legendary dirtbikes from the past. (cool issue....lots of memories were conjured up)
Anyway, in there they have a picture and artical about an old Kawasaki 100 that used rotary induction. They stated that it made more power than most 125s and even as much as some 250s! My dad had one of those when I was a kid. But then they went on to say that Kawasaki abandoned the rotary induction and went to reed valves. I wonder why a giant concern like Kawasaki, or any of the dirt bike manufacturers don't produce a rotary system any more? If it truly is superior you would think racing bikes would use it, but they don't.
Wiz