I have always found keberoxu to be very kind, caring and interesting too. But it's sadly true that some people on Mudcat see the forum as a sort of virtual boxing ring and have to have the last punch every time.
I think it boils down to each individual's personal manners and character. Some folk are naturally pugnacious and confrontational. I expect in real life they're a bit prickly and readily bite back when they don't agree with a comment.