The presumption you made is that DaFranker should be expected to push himself to implausible extremes of tolerance, patience and rational thinking so that he is somehow able to resurrect the possibility of communicating with you. This kind of expectation is the opposite of what it takes to adapt to communicating with normal people.

That a belligerent tone precludes/hinders most people from parsing the actual content and limits them in their immediate rational thinking capacity is - to me - a clear failure mode which, as you say, is unfortunately characteristic for "normal people".

A belligerent tone does obviously in itself convey certain information, mostly relative to status squabbles, and should be filed away for future reference, not ignored. However, it shouldn't impede the reader's capacity to engage with the argument beyond that tone, and the simple fact that it does constitutes a bias - a cognitive impediment - to be overcome.

Engaging on important topics is hard enough and shouldn't be a training ground for "learning to deal with belligerently presented arguments on the content-level", however it's a useful skill that should be acquired. Otherwise we'd let emotions continue to cloud our judgement, as the Jedi would say.