Is it really this community's intention to require comments, prior to down-voting? I was unaware of this. Is it documented in any official pages (e.g., any side panels or the site's Tour page)? (This prior answer is relevant, but not definitive, nor sufficient in scope to address this inquiry.)
Does a majority (or perhaps majority of Moderators) really subscribe to this notion? I can see the argument and perhaps it might indeed make people feel better (which I naturally do consider important). I never personally viewed a down-vote as particularly negative nor rude, however—simply an efficient mechanism to express one's preferences regarding a question or an answer, and to effectively motivate improvements or (mostly) signal extrinsic accuracy.
How does this putative policy differ (if at all) for questions, vs. answers? How does it differ concerning old questions, for which newer information or additional research might be relevant? Are users really expected to have to engage substantively, prior to their being able to express a hopefully constructive preference? In particular, is it not desirable to allow quick expression of preferences, for users willing to express them (and take the Reputation penalty), especially in situations in which an answer is old and may be improved? Is the onus to suggest edits or to comment really to be delegated to the user, as opposed to merely being preferred?
In this particular situation, I had admittedly not initially noted that I was down-voting such an active user. So naturally, more constructive engagement could have been preferable. Nonetheless, I am surprised that this appeared to be interpreted negatively and might be contrary to policy.
This seems to run contrary to the usual practice across Stack Exchange or at least how the model is generally outlined and presented. If this is to be the determination of the relevant quorum, perhaps this ought be more substantively outlined and documented?