There is definitely something wrong with doing that with a top-level comment. It distracts from the actual topic. You should only do that if you have a very good reason, such as noting the same behavior multiple times on multiple topics.
You should certainly not do it within two hours after the article was posted, to allow time for selfcorrection. That is the point of the voting system.
There is also something wrong with doing it in an appeal-to-emotion fashion, threatening how this is 'almost making you leave'. You should clearly address the problem at hand, citing examples and explaining the problem, instead of hiding the actual problem that the fuss is about in the third paragraph.
You should only do that if you have a very good reason, such as noting the same behavior multiple times on multiple topics
A top level comment seems to be the only appropriate place to discuss the overall tone or tenor of a conversation. Responding to each dismissive/negative/unconstructive comment seems redundant and annoying.
How about you don't respond to tone or tenor at all? It's a bad argument on the best of days (PG's hierarchy has that near the bottom, one step above straight up ad hominem.)
It's a diversion at best. If you feel someone is being unpleasant, deal with it. You needn't be pleasant to be right. If they're being unpleasant and wrong, reply with why they're wrong, or alternatively downvote and move on. No need for meta noise in any case.
I respectfully disagree with the idea that we should simply ignore unpleasantness in the community. A healthy ecosystem is determined by a lot more than mere factual correctness.
But it's also determined by a lot more than a veneer of politically-correct pleasantness. I suggest that the best way to deal with such people is use the downvote button. Complaining about tone is just so much noise... it adds nothing to any discussion.
You should certainly not do it within two hours after the article was posted, to allow time for selfcorrection. That is the point of the voting system.
There is also something wrong with doing it in an appeal-to-emotion fashion, threatening how this is 'almost making you leave'. You should clearly address the problem at hand, citing examples and explaining the problem, instead of hiding the actual problem that the fuss is about in the third paragraph.
Too little content, too much drama.