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Even when they nerfed the sleep mechanic after gen 5, it is still a pain to deal with. Most of the complaints regarding dire claw pertains to sleep. Putting a potential win con out of commission and even become a setup fodder really sucks.
Regarding the Dire Claw situation, it's just better to ban all sleep inducing moves in general. This includes Spore, Sleep Powder, Hypnosis. Nobody likes getting their mon put to sleep anyway. I'd rather deal with para than sleep.