I suspect if you show this thread to enough random people, a clear majority opinion will form on whether that comment was snarky and unkind. The language in the Guidelines isn’t objective, but I also don’t think it’s all that difficult to understand if you were taught the difference between being forthright and being sarcastic, and the difference between being gracious and being unkind.

Of course some people will get angry and defensive when they cross the lines and get called out on it. That’s just human nature. (YouTube is chock full of examples.)

It doesn’t mean enforcement isn’t necessary, though. The owners have made it clear that they don’t want this site to devolve into a free-for-all full of sniping and bile. Their house, their rules. Want to be a dick? There are other venues for that.