Bringing up a reference it's the stupidly big muzzle, lack of a snout, and massive proportion of its head to its body that makes it hard for me to see a Squirrel. Pachirisu has a more simplified head shape and face, while exaggerating the tail proportion more.
Greedent also has the issue where I think the face is too detailed, with the extra muzzle, dimples/freckles, and longer-proportioned arms invoking too much of an uncanny valley feeling vs Pachirisu as a cartoon squirrel. Eevee gets away with its design for the same reason, mostly being a bunch of simple round shapes.
I think it's weird you mention the tail when greedent def has a larger tail to body proportion. The rest are opinions of course, but jumping from "it's design is a bit of a mess" to "this peter griffin idiot is the ugliest thing in the franchise" is making me giggle.
I'm not interested in defending greedents honor, this guy gives me 0 feelings and I only know it exists because I have pokémon autism and I love knowing all pokémon, but to me this is some of pokemons most inoffensive, safe, generic designs theyve made since like gen 1 seel and raticate. Ultimately its all opinions but the vitriol is what makes me laugh. I'd rather greedent get hate than my homie bruxish tho