>>56754242mix of both, probably
Given that furry culture indulges hard in the aforementioned brightly-colored animals with very obvious expressions, I think there’s a solid chunk of autistic furries who are just furries because they feel “safer” around neon-colored cartoon animals than around other humans.
Then there’s more the chris-chan type that’s gone so hard into the fantasy that they can’t picture anything outside of it, hence the weird fetishes and the sexual imprinting.
There’s also combinations of both (which you could argue Chris also is), especially common in Sonic/Pokemon because they’re unified by the same franchise of neon-colored animals with relatively lenient gameplay, and these tend to get the most attention because they’re the most eccentric.
That plays into the grooming angle, where these eccentric sexual extremists get a lot of airplay because the “normal” autists who just like the animal aspect aren’t nearly as loud and the really degenerate ones tend to drive away more normal autists.
Those eccentric standouts then go on to groom others (even unintentionally, just by getting their fetish shit exposed to such a wide demographic), which perpetuates the cycle and further amplifies the eccentrics, which leads to a big tumble-down domino effect that has leaked into modern day where basically every other autist (ESPECIALLY online) is now some form of furry or fan of furry-adjacent material.