It's a fair point to make. Why not just have some buff man walking around shirtless all the time. That's the same sexist logic of the catsuits.
Seven of Nine was an interesting character, but the catsuit really distracted from her.
Leeta was just a bimbo in revealing clothing and Quark made no qualms about it.
T'Pol was just a wooden Vulcan who's catsuit failed to compensate for lack of personality.
Personally I'd rather have a fat person in a burlap sack who's interesting than a hot person who brings little to the episode beyond their looks.