I don't understand it; save that people just no longer 'see' the threat; just think it is more fun than the bike they rode on as a kid, perhaps.
A horrible tragedy and horrible suffering for everyone who shares the pain of this. I am sorry for all of them. .
Children are not safe 'driving' golf carts either; yet, have seen the most unbelievable 'drivers' entertaining themselves on a golf cart. Adults can be killed/maimed on these things; and yet, not unusual to see kids enjoying their 'freedom' with parental approval.
'NO' is not a bad word; but some parents have a hard time with it.