Except Snorlax saw more usage than Hippowdon this month? How is 27th in usage uncommon...but 33 isn't?
Besides, the metagame is highly unstable right now (as the huge differences in October and November statistics shows), so none of this is set in stone and Curselax could shoot right up like...say...Rhyperior did? It's awfully silly to mention some walls but write off others in a highly unstable period, especially when the difference is very small (4:5 Cresselia/Hippowdon ratio is very small and likely to change).
And despite lower usage, Curselax is tremendously more threatening than, say, Hippowdon (who can't do ANYTHING offensively without a CB or something along those lines). That combined with it being easily OU makes me wonder how it can taken any less seriously than Blissey since Blissey...well...can't hurt anything.
Check out the usage statistics on smogon, its a sticky in stark mountain there.
Even ResttalkLax should be considered since it IS a wall after all. lol