I agree with the fact that there is nothing to be done about runners. I am a wushu player myself, and it really isn't the end of the world if you encounter a runner. If you are the better player, then you should be getting more points during exchanges. Running won't be a problem. If you aren't as good as the other, then you don't deserve the win regardless.
Let's just leave ruining alone. As sir said, this is the same as shoveling in aikido. You can't ban a plethora of people because they are using an effective strategy.