I'd suggest to knock off the rudeness.

I'm not saying to ban it by the rules, just raise the barriers a bit or add a barrier -- those seem like good ways to do it. Basically there are ways to force technique, like forcing run-ups.

Your comparison to crashes on descents doesn't work. Crashes on downhills are a part of riding -- gravity, hills, there ya go. It's not comparable to a risky optional technique.