Also, the only reason the author would expect their comment to be downvoted is because 1) its insightful, but unpopular and 2) because the author knows right well that the post adds little value, is off-topic or detracts from the conversation.

If its #1, then you must clearly state your argument. A well thought out, but unpopular, opinion normally doesn't get as many downvotes as a not so well thought out opinion.

If its #2, then maybe the author should simply refrain from posting.