I don’t have much time to answer this from work. But you should read again what I wrote (since, as you say, wording matters). I spent several minutes getting that phrasing right, actually:
Also, you are excluding a large middle region. There is a lot of open ground between ‘humble’ and ‘rude’, and in that region there are both ‘courteous’, ‘civil’, ‘direct’, ‘to the point’, and ‘chilly’. Requiring that posters should be ‘humble’ in the face of rudeness (and even personal insults) is unreasonable.
In order to try to understand what I actually mean, ask yourself: Does the tone of the person you are talking to never influence your own, in any way or degree? Shouldn’t it? Are you equally warm and cordial to everyone, always and all the time? This is what I am talking about, not being rude yourself, but allowing your tone to cool in the face of rudeness.