When you put it into perspective, Hail-Endeavour-Room isn't IMPOSSIBLE to stop. I use Prankster PerishKrow because it is generally slow enough to outspeed a sizable amount of Pokemon in TR, won't be doing any damage to boost Endeavour's power through the roof quickly, doesn't mind Hail because of Roost, and can Perish-Trap just about anything in or out of Trick Room because of priority.
And another beef i have with the potential ban is that, wouldn't it count as that one thing Smogon is trying NOT to ban? uh...whats the term...oh yeah, a Complicated Ban? Just my own opinion here.