Yeah, there's a difference between cosplaying a character meant to be sexy, and a stripper wearing a sexed up version of a costume she knows nothing about, just because somebody paid her, and is calling the result "cosplay".
I admit, I'm not a fan of the sexy female genderbends, but that's because I think the costumes don't really fit the personalities of the characters- Thor wore sensible armor, as opposed to running around bare chested. And Link's tunics looked like practical clothing. Surely there's a way to make those costumes more flattering to the female form, without defaulting to "make it skimpy". But that's a design thing, not a comment on the morals or genuine fannishness of the ladies in those outfits.