Are my parents stupid? They bought my brother a motorcycle...?

My brother came over to visit he is only 17 mind you and he pulled up on one of those Kawasaki speed bikes. I was so boggled out seeing him on that and all and i asked him who bought it for him and he said mom and dad and that it was like 9k. So rather then buying him a car with a shell around him they buy him a crotch rocket. I do not understand my parents thinking with this. Would you buy your child something like this? Cab someone help me understand the logic behind this?