I'd argue that the context matters a lot here. If this were just a normal conversation between me and an actual redditor, then my remark would have been justifiably seen as over-the-top (though permanent suspension is imo a big overreaction). But in this case it was an obvious, provable shill sea-lioning in the middle of a conversation between others. What I said would have been more or less like telling some random door-to-door salesperson to fuck off and die. Harsh? Maybe, but maybe warranted given their intrusion (especially if you consider what they're shilling for). But that's not acceptable. Today's social media is modled not after a town square or an old-school bulletin board or even just a chat -- no, it's modelled after a Shopping Mall, where the point is to expose everyone inside to as much and as powerful of manipulation as possible by those who pay the owners for access to the sheep. And you are not to resist any kind of approach, provocation, or shilling, but sit back and drink in the ads.