I am not obliged to ignore someone's bullshit-artistry. Better to repeatedly point out why he's a bullshit monger in the hopes that someday it might sink in. At the very least, his bullshit doesn't go uncontested.
Actually yeah, the "bullshit" does go uncontested when you fail to address it and instead derail to personal attacks on the "bullshiter" instead of contesting the "bullshit".
Not so.
To take a completely hypothetical example, imagine some poster (maybe on stormfront) posts the following:
imaginary_racist said:
All the Jews should be rounded up and shot, because they are responsible for killing Christ
Now, there are three responses that we could have to this:
1) A detailed rebuttal, that analyzes the meanings in the original statement (who was 'Christ'? did he even exist? Can today's Jews be held responsible for actions that occurred thousands of years ago? etc., etc.) - But who has time for that? This fucknuckle isn't going to read a long and detailed rebuttal, and he won't accept its conclusions even if he did read it.
2) Ignore him - This is your recommendation, and it certainly has some merit. BUT, we need to consider what effect it has on both the poster, and on third-party lurkers. They see that the post has gone unanswered, and may think 'Well, nobody is saying it's wrong, so perhaps he is right'.
3) Respond with a personal attack - "Oh, fucking stick your anti-Semitic crap up your arse you fascist wanker" or similar. Of course, that in no way rebuts what was originally posted; It doesn't form a counter argument. But it does indicate to the poster, and to lurkers, that the opinion originally expressed does not have universal (if grudging) support.
Of course, option 3 can ALSO constitute 'virtue signaling'; But that need not be its only (or even its main) purpose. Indeed, it is the reverse; it is signaling the
lack of virtue that the original poster is demonstrating.
Sure, it would be nice if we lived in a world where reason and logic were always used in debate. But we don't; and so the well judged insult can be as useful (or even more useful) in advancing a case as a detailed rebuttal of an erroneous belief.