There are reactions to their bodies. Muscle mass gets mentioned a lot.
Generic NPC's don't talk specifics so won't even comment on MC's body, conversations come from named mobs. MC's group mention enemy bodies.
The main reactions to anything are usually between the group you travel with and named/unique encounters.
Generic cannon fodder are purely that, cannon fodder. You won't get anything more than a "please fuck me" after beating them regardless of body parts.
You're expecting a bit too much from random mobs.