Is it really a new thing, or have people merely found a new label for mildly critical posts that allows them to dismiss them out of hand?
I think the real plague might be the constant cries of "concern trolling!" Any kind of posting that is based heavily on speculating about another poster's motives rather than making a contribution on the topic of the thread is cancerous.
I mean, there are probably a few posts that really are disingenuous expressions of concern, but the term is now so abused that we'd all be better off if we just ignored the concerned citizens and stayed on topic.