First and most important: we're in a shitposting community. This is not some stage where the conversation needs a focus. This is THE place to call people out casually. It's a damned free for all for better and worse. I'd honestly be more OK with your argument if this happened elsewhere. I'd still disagree, being polite and ignoring people being shitty in public should be called out more, to hell with face. Holding people to basic standards should be the norm and doing so where others can see shows those that might be hurt that people don't agree. But elsewhere, I'd consider removing my post or some such.

You're right. Most insults have someone who may be hurt who doesn't deserve it. I've honestly had that thought bouncing around my head for the past hour or so. And I don't have a good answer other than calling them things are/should be universally reviled. Work in progress. Immoral shitstain has a decent ring and I suspect there isn't anyone that identifies with profound uncleanliness. The ideal would be to specifically insult based on bad behavior, but damn that's tough on the fly and very context dependent.

It should be noted, and you did somewhat, that calling someone and asshole or fucker doesn't have a storied history of being a slur. I'm no philosopher or even terribly good debater to specifically define the line, but 'old slurs that came back because awful people started using them again' feels like an easy win. We gave that word up a long ass time ago, let it stay dead instead of emulating these people we claim to loathe.