(I don't want to come across like I'm nitpicking because no, to be clear I'm genuinely interested in this.)

That many communities are hostile to the devs shouldn't be surprising, because unfortunately the lemmy devs are openly bigoted and most communities don't like that. And that's ignoring how Des is also a genocide denier and dismisses the human rights abuses of china while championing authoritarians (ex: their profile banner is currently an image of Mao), things many communities explicitly do not allow.

Without knowing which user you're referring to I can't speak to the scope of what they're doing, but a single user isn't exactly evidence of hate groups or hate communities specifically set up to target the lemmy devs. That's just reprehensible people being criticized, and then one potentially freak user taking it beyond what is reasonable.