In five years, I've been knocked down by snowboarders three times. They always say the same thing; Dude you were in my way, or my favorite, "I was going straight".
I don't know how many times I've heard boarders behind me announcing that they are going straight. They seem to think that if they board the fall line, everyone has to get out of their way. Maybe it's becasue they are able to look behind themselves, they don't understand that skiiers cannot do this, and the term 'I'm going straght' is meaningless to someone behind a skiier.
Collision management was a formidable problem before snowboarding. Snowboarders have made the problem even worse, mostly due to lack of education regarding the rules.
Furthermore, novice boarders are able to negotiate terrain that takes years of skill developemnt for skiiers, which makes getting away from them problematic.
You can't run and you can't hide. The only thing left is to ski in the spring when the crowds are gone and everyone can give each other wide berth.
I think the problem with boarders is not that they're on boards, but that they're generally teenagers -- with all the "want to wring their insolent bastard necks" feelings that implies.... ;-)