This is the start of the thread. It is pretty obvious that no one is being serious about actual violence. It's just banter. Harmless (and not at all unhealty) banter.
The type of communication in the LKML has always been straight to the point and without unnecessary diplomacy. Sometimes it reads as assertiveness, sometimes it reads as rudeness. The point is that it works.
Every community has its "rules". Those rules are made by its members, all its members. If you disagree, act differently. If you are right and the others are wrong, they will follow you.
Asking for "professional behavior" when others are just acting normally is whining for politically correctness, which is pretty annoying and a sure way to not change anything.