It sucks because it loses to pretty much everything in OU. Celery, Suicune, Vaporeon, Hippowdon, Skarmory, Machamp, every electric type, Gyarados, Metagross, Jirachi the list goes on and on lol. It sucks because it's stats are terrible. Balanced stats arent good in Pokemon unless you're "Balanced Stats" also happen to be totally broken(WHOOOOOOOOOOOOOOOOOOOO heatran) Its movepool is also shallow, it doesnt get any good support moves to use with its bulk and it doesnt get any decent physical moves to use in tandem with Bulk Up so it will never get past physical walls.
It doesnt suck because it's UU, it's UU cus it sucks.
Anyways, answer my question. Doesnt the fact that your counter only may or may not work depending on what set your opponent is using for THEIR pokemon mean that they should all be banned? If you ban mence for that reason you have to ban everything else or you're playing favorites.