Suppose he is being treated unfairly by the mods. Is that not worth complaining about?

I don't give a crap about some silly "downvote every comment complaining about downvotes" rule. Complaining about downvotes was frowned upon because people get inexplicably downvoted as a matter of course here, and the frequency of complaints was deemed sufficiently detracting to warrant being frowned upon. Being treated unfairly by the mods, however, is another matter entirely.

I haven't seen a preponderance of evidence suggesting the complaint was ill-founded, and the guy's tenure and comment history (what I looked through of it) do not suggest he's an ill-mannered troll, so I reserve judgement as to whether the complaint is in the wrong. Like any reasonable person would.