I'm usually pretty quick to downvote low-quality posts that I don't want to see again, but which I'm afraid others will refrain from downvoting because the comment is also disagreeing with the groupthink and the others will start questioning their own correct quality judgment.

What should really get the upvotes are the high-quality comments that disagree with the groupthink. These are the precious heroic ones. Don't set that standard too low!