I do not think that is the right question. This is supposed to be our hobby, not our profession. (I am not debating or suggesting whether Jack has a thin skin or a thick skin. I think that is irrelevant. "Skin thickness," in my opinion, has nothing to do with this.) Even if an audiophile has a thick skin in his profession it does not follow necessarily that he should also have a thick skin, or want to have to have a thick skin, in his hobby.
It is a simple cost/benefit analysis. If the costs to a member of participating in WBF (aggravation, time, annoyances, dealing with ignorant opinions or rude comments, etc.) exceed the benefits of participation then that member will leave. It is as simple as that.
I followed Jack's posts closely, so it is unfortunate for me personally that he left.
I avoid posting on threads which have devolved into combativeness and impolite contentiousness. For me, those particular threads have costs which exceed the benefits of reading them.