It is good to be reminded of the reporting function. I too was not aware that there was such a function and I am glad to know of it now. But, I would worry that reporting some criticism of me, or aggression towards me by another for whatever reason might cause more problems than the situation calls for. I am reminded of the most unpleasant experiences I've had in restaurants is when then waiter or server asks the question, "was everything wonderful???" with a smile, and I make the mistake of being honest and say, "well no my dinner was terribly prepared." Big mistake. The manager comes out to aggressively defend their staff and argue the point and everyone ends up much unhappier than if I had just let it go away.
I don't know why members are banned from this site. But, I definitely think that the "death penalty" of banishment is a very heavy handed remedy if somebody falls off the wagon. That is too bad that this has been resorted to and the punishment is too harsh in most cases. I hear bbBD is banned now and I remember when a couple of other very active members were banned - Everso and Supermarky - and I knew they could be highly critical of others. But, If someone like bbBd can be banned for having a bad day with someone, then it is probably too much punishment for whatever the crime. He was one of of our best members all the way around in behavior and conduct as far as I could tell.
It may be asking too much of people to not create controversy with their words while in discussions. I have watched many of our best members and moderators as well, be just too aggressive at times. But, no need to limit personal opinion or expression of passion. Personal insults are never proper, but surely it would take less time to simply ask the people to fix it or resolve through the pm process, instead of just banning them.