Hmm, I wonder. I have an inkling of a theory:
Animal-Human hybrids with animal heads = no respect
Animal-Human hybrids with human heads = respect
So, for example, the harpy and sphinx and centaur would get respect, but not the hieracosphinx or a horse-headed man.
I think you're definitely on to something in the collective unconscious, here. Absolutely true.
We 'like" the familiar. We "fear" the unknown i.e. the strange or 'too' different from our norm. Human [or human-esque, like elves, et. al.] head/faces definitely receive a favorable reaction to those things we do not immediately recognize...and thus "relate" to. Even going right down to the majority of "good bestial creatures" like shedu (full bull body, wings, but a human head/face), lammasu (lion body, wings, but a human face/head). Mythological/real world ranks of angels, supposed to be known/interpreted as mysterious and powerful, barely fathomable...human bodies, wings, animal heads.
The wings, themselves, too! Feathered wings? Awwww. Birdies! Bat-like or stretched skin (pterodactyl-like) wings? EW! Scary! Gross!
Centaur: Human head and "well-formed" muscular torso + Horse body? Horses are noble, helpful, useful. They can be "wild" or "domesticated" [which is comfortable, familiar, not harmful -for the most part]. Centaurs = COOL!
Drider: Elfin (even DARK elfin) head and torso +
Spider body?! Spiders are creepy, silent, deadly. They have abilities: climbing, sight/multiple eyes, web-spinning, poison...like
nothing humans can do or duplicate. Drider = AHHHHH RUN away! RUN away!
"Scorpionmen" identical reaction.
Lamia, same thing. Human[oid]] head torso, female even! + combined/unknown "beast" or snake body? Bad, bad, very bad...and naturally, since "it's" female, there's
that level of added "strangeness" to male minds. So it can charm/seduce/deprive men of their senses: lamia, harpies, sirens, medusae, nymphs, fairy beings of all sorts, on and on throughout [mostly mediterranean/occidental, it seems, though a few asian creatures apply as well] myth.
Still, they are not considered as horrifying or badwrongstrange to our unconscious as, say, a giant [like "Shelob" giant] spider *shudder* or a chimera [rotsuv non-human monsters all rolled into one!] or in direct contrast to centaur, the minotaur! Human body with a BULL HEAD?! It eats us? It knows things we don't/can't possibly know [maneuvering the labyrinth]? It's bigger and stronger than almost any of us can be? Nooooooo!!!!
Suffice to say, I think your "theory" is much more reality than you have realized.