I am not an electrician but I have been in the electrical/lighting industry since the 80s. I do not understand Part P, know what Zs are or anything about cable. However I have a braod based knowledge of the industry & certain products. I therefore feel capable of posting on threads which are within my remit. I would not comment on things which are beyond me.
However the problems seems to begin on this forum when people come on here exaggerating or lying about their qualifications & abilities & trying to do electrical work far beyond their capabilities.
Give my limited knowledge, even I can tell when people are getting in over their heads & may carry out work which could be dangerous or lethal & should only be done by a suitably qualified electrician. This is when the "bad feeling" starts & some people persist, fail to take the hint, get in a hole, keep digging & rightly get flamed for it.
My own view is that to some extent these people deserve what they get although some of the comments have been a bit OTT & could have been better expressed.
What is unacceptable are snide comments, backbiting, sarcasm etc. which do the forum no favours. I think we should all look at ourselves & reread our posts before pressing the reply button.