I agree with most of what Pierre has said. By the time kids can honestly be called racers, they have developed abilities that allow them to ski at a faster speed with a greater level of control.
I've never been hit by a racer, and I've been around enough of them in very confined spaces. I have, however, been hit by skiers with lower ability that were skiing above their limits.
Running human slaloms on bunny slopes is never acceptable. However, skiing fast AND in control on trails that are wide and relatively uncrowded is acceptable in my opinion.
Most race coaches I know preach skiing slow and in control to their racers while they're out of the course. However, youth does play a factor, no matter who the kids are affiliated with. Do you think those kids would exhibit any better judgement if they weren't in a race program?
I'd rather see a group of juniors approaching me at high speed than your average intermediate. How about the kid on twin tips popping every bump in the slow zones or dropping onto groomed slopes out of the trees without first spotting his landing?
The problem as I see is children. They just don't listen, so they should be prevented from skiing. The only people allowed on slopes should be Volant owners that like to make slow turns and buy condos. I own a pair of Volants, so I should be half qualified.
Now as far as I'm concerned the rudest people on the hill are course poachers (pet peeve).