Nah, they're just lazy buggers. Asked the son of a friend if he wanted to go for a ride with me. He didn't because a: I ride up hills before I ride down and b: I'd probably beat him downhill and embarrass him in front of his mates. He's 22 and I'm 48. He rides a nice BMC dual sus bike, I ride an almost original 1990s Giant ATX840 I scored from a mate for a 6 pack... he's just a sook, if you can't drive to the top he's not interested. Interestingly I offered to do a car shuffle ride, but factor b: still came in to play. Bit silly, the way to go fast downhill is to be fit from riding up hills.