I agree that this is a good idea. The Discourse flagging system combined with the diligent human modding has made this BBS one of the better ones out there, but there’s always room for improvement. The flagging system does not really catch members who consistently argue in bad faith (and who’ve been emboldened by a wider political climate that allows if not rewards such behaviour).
Since such a flag wouldn’t be as clear-cut as off-topic or inappropriate or spam posts, I’d also recommend a mandatory freeform text field similar to that of the more broad “Something Else” flag for the user to briefly explain the reason (e.g. use of specific logical fallacies, citation of false facts from disreputable sources, disregarding inconvenient facts from reputable sources, comments that are more about attention-seeking than contributing to the discussion, etc.).
The mandatory field would discourage hit-and-runs, reduce the risk of brigading and, reviewed together behind the scenes, might serve to alert the mods and admins to patterns of behaviour for the member in question. The flag would also push some of the drama and frustration we see over bad faith arguments to a more appropriate and productive place. I’d go so far as to suggest that, if the system would allow it, the threshold for hiding posts be higher or not enabled at all so that the admins can take action (from gentle private warnings to suspensions) as they see fit.
