As a Sinister-American, I find that language to be hurtful, besides, the phrase is “left-handed compliment”.
Anyway, to the point of the thread, I think I am about 78% in agreement with the OP. I do see discussions get heated, and barely concealed insults get thrown about, under the guise of “attacking the post, not the poster”.
However, I would not necessarily change the rule, simply change its interpretation slightly. Being hostile is being a jerk, but there is a whole lot of hostility that goes on that flies under the radar. I’ve tried reporting it in the past, but it is considered unactionable. The only way to respond to a post is with hostility of one’s own, or to bow out of the thread.
After having received no mod notes, but apparently had been flagged, I got warned, with those flags, but not a single mod note, as the precedent for it. I simply felt I was giving as good as I got, returning the hostility directed at myself, which is never modded in kind. Apparently I was wrong and copped myself a warning for crossing a line that I felt others had crossed, been reported, and nothing happened, on a regular basis(I am not disputing this warning, I admit I crossed a line). I had stopped reporting such hostility long ago, as it was never acted upon, and after the warning, tried for a bit to calibrate where the mods draw the line, but have given up again, as being told that “Butter wouldn’t melt in my mouth” and reporting it only had the action of a mod saying that defining Socialism was a hijack to the thread.
Pretty much, the unmoderated hostility of GD and P&E is the main reason I stay out of such threads anymore. People impugn nefarious motives or comment on the mental state of other posters all the time without sanction. Characterizing an argument as “bullshit” is still pretty hostile, but it pales in comparison to much of the other stuff that goes on that is considered to be acceptable.
I like discussing things dispassionately. There are very few topics that I get worked up about, very few things that, on their own, make me angry or upset. The method that some posters choose to discuss these topics, OTOH, sometimes does.
You can be passionate without being hostile. There are science or space based threads that I would actually characterize myself as quite passionate about, and those are the threads where others who are passionate about the topic come to discuss it with very little, if any hostility. There was a fair amount of passion expressed by a number of posters in a recent thread about knives and their care, and yet no hostility.
TL;DR, the interpretation of the “Don’t be a jerk” rule should be updated to include hostility as jerkish behavior.