What I did
I left a comment on this answer explaining that I downvoted because of the recommendation for cussing out your superior. It also contained a speculation about what a preceding comment was intending to say. My hope was that the author would revise the section, but even if not, I believe that the criticism and clarification of a previous comment are a legitimate use of comments. (The section has not been revised, so it's not obsolete.)
It read something along the lines of
@WGroleau I believe slebetman may be saying that the stream of profanity would cause this. (That is, quitting could become fired with cause.) I was going to upvote this post until I saw that part. If you would quit over this, just hand in your resignation and make it clear that this treatment is the reason why. Don't cuss out your superior. -1
(I'm certain that isn't quite exactly what the comment said, but it's the general idea. I have no problem if someone can obtain and wants to post the exact text to discuss it.)
What I'm confused about
The comment has been deleted (potentially twice, I'm not 100% sure), while the comments preceding it (and apparently following it) remain. So my comment was singled out for deletion. Why? I do not understand why the comment would be flagged, much less what justification for deleting it there was. Did I do anything inappropriate?
Why this isn't a dupe
It's been suggested that this is a dupe of What "comments" are not . . ., but none of the reasons there explain why it would be deleted.
- Comments are like Post-It notes The comment pointed out a problem with the post, namely that cussing out your supervisor is inappropriate enough to warrant downvoting the answer, in my opinion. So it is clearly relevant.
- Comments are not for answers It clearly wasn't an attempt to answer.
- Comments are not mini chat rooms It's not chatty. It was specifically targeted to a problem with the post.
- Comments are not discussion forums No debating or deliberation. Just, "That specific thing in your post is a problem."
- Comments are not for voting No, they're not, but one of their purposes is for explaining problems in a post. That I also took the opportunity to express the fact I downvoted for this reason does not invalidate this fact; it's an indication of the severity of the problem.
- Comments are not for Meta discussions Also not applicable.
So none of the discussion there explains why this comment would be deleted.
Is it constructive?
I believe that everyone reading this is capable of the making the extraordinarily small mental leap from, "This single, isolated part of your post caused me to downvote," to, "This single, isolated part of your post should be removed or edited." I don't think that needs to be made explicit. I even suggested a more professional alternative behavior that could easily replace the unprofessional behavior mentioned in the post. Realizing that I meant that the post needed to be changed is a sufficiently small leap that I have a hard time imagining anyone not making it.
Additionally, I expressed that with the exception of that one small part, the rest was a very good answer.
I'd also like to add that there's no hiding behind, "It wasn't a suggestion," to suggest that it can't be criticized as problematic. (A comment here made this point.) If the author did not wish to express that they considered the behavior appropriate, there would be no need to include it in the answer.
Is it nice?
The Be Nice policy does not forbid strong criticism of suggestions/promotions/expressions of approval for unprofessional behavior. Neither does it forbid expressing that one specific unprofessional piece of an answer was the sole reason I considered the answer bad enough to warrant a downvote and at the same time expressing that the rest of the answer would have been good enough to warrant an upvote. I made no personal attacks, and I offered an alternative professional behavior. I see no reason to consider this "not nice."
Comments are temporary/ephemeral
If the entire chain of comments had been deleted instead of mine singled out, I would have assumed this explanation myself. Appropriate comments are often lost amidst a large number of inappropriate ones. It's happened to me personally before. However, this time, my comment appears to have been specifically targeted for deletion, while the rest of the comments around it remained. This suggests to me that somebody (a person who raised a flag and the moderator who approved) considered it more problematic than the other comments surrounding it.
Why am I so bothered by this?
So I'm still left wondering why a person would flag this comment or why a moderator thought it warranted deletion.
The only speculative answer I have about why it would be flagged is that whoever flagged it simply didn't like the fact I criticized using profanity against your superior. But this is completely speculative, and it wouldn't explain why a moderator would approve the flag. However, I believe that if (and that is a very big if) that's what happened, the system has been abused. That's why I consider this issue important and why it's equally important for me to figure out if I'm in the wrong instead.