I think it's the riders who ahve ridden 2 strokes are getting older and wiser that realize the 2 strokes are just plain FUN to ride.
Now as far as Kim's post about the 125 (nothing personal). I really can't see any of them riding a 125 because there just isn't enough power to really give them a rush. They would literally twist the grip off or break the cable trying to go faster. But a 250 would be enough for them to have fun and a well built 250 would provide more than enough for them to compete with a 4T.
Besides, it's more fun to be wide open, ripping than lugging up through the powerband.
IMHO, screw thumpers. They make you lazy.