Going back to the topic at hand, I think the point that the thread opener raised here is very simple, criticism vs bashing and where the lines get blurred. Constructive criticism is healthy for any society, as long as we personally identify with the issues and discuss how it effects us, when we do that in a cohesive and logical manner it makes sense because we take into account both negative and positive aspects. When only the negative is 'discussed' at length over n over again, it paints a one-sided picture and borders on bashing.
"Discussing legitimate concerns" is definitely a huge part of why these forums exist, as long as these concerns do not take a judgmental tone and people do not start abusing this platform to vent their personal frustrations without any merit, to support their arguments.
There you go! :)