Couldn't agree with Lankee & K J more-it's a combination of both the parents & the kids/squids.
1) Parents shell out the coin, usually as a reaction to the quilt trip the kid lays down, "all my friends have them, and it's ONLY a 600....."
2) How much experience driving high powered motorcycles can a 17 yr old kid have?
It's a quaranteed recipe for disaster!
The worst-a buddy went down when his mid 70's Kaw triple death machine went into it's famous speed wobble. He tumbled & slid for over 400 feet, wearing sandals, shorts and a t-shirt. Very few bones broke, maybe an ankle or two and a wrist, but of course nearly 100% of his skin was left on the blacktop.
They gave him 'last rites' figuring he wouldn't make it thru the nite, but he survived. Recovery was months of infections, kidney failure, skin grafts, on & on.