Sex and lust, while related, aren't the same. One's an act and the other's an emotion. Functionally, they have similar differences. The aversion to sex is largely (though not solely) about the physical problems that may occur, while lust is about corruption of the mind, and the social problems that stems from it. Sure, there's a thematic overlap, but they're different beasts.
In the case of this trope, it's about how the intent to inspire lust is evil, i.e. dressing sexily. I'm not sure if it's really different from Sensible Heroes, Skimpy Villains
, other than lacking the contrast aspect, but on the other hand, that would make it a supertrope. And to me Sensible Heroes, Skimpy Villains
is basically just a way to show this trope off more clearly.