My last post on that thread pretty much sums up what this is all about:
This is a clear example of the so called argumentum ad hominem which is a logical fallacy that involves an argument against the person, in the form:
Person A makes claim X There is something objectionable about Person A Therefore claim X is false
Even more this is an argumentum ad personam, that involves insulting or belittling one's opponent, but can also involve pointing out factual but ostensible character flaws or actions which are irrelevant to the opponent's argument