Many of our terms of abuse are founded on body parts or activities that are not insulting to attribute literally: “You’re a prick” is abusive, “You have a penis” is not; same for “You’re a cunt” versus “You have a vagina” and “You’re an asshole” and “You have an anus”; “You shit” as an epithet is angry, but as a statement meaning “You defecate” is boringly true; “You’re a fucker” is impolite, but “Literally, you copulate” is, for most people, not unflattering, though it may be a bit personal.
On the other hand, “You wanker” may produce less of a blush than “Literally, you are a masturbator.”
You can try this at home. Take something rude and vulgar, change it to literal technical words, then do the same with an equivalent masturbation reference. Gauge the varying effects:
You dumb-ass motherfucker.
You unintelligent-posterior mother-copulator.
You dumbass motherfrigger.
You unintelligent-posterior mother-masturbator.
Are you just fucking around?
Are you just fornicating in the vicinity?
Are you just jacking off here?
Are you just masturbating here?
Go fuck yourself.
Go fornicate with yourself.
Go wank off.