I think there’s value in it. The underlying idea is that if someone is wrong, even if blatantly so, you have to take the effort to explain why. On reddit, the downvote button was just as often used as a community cudgel against dissenting opinion, even when the opinion was 1) genuinely harmless but unpopular, 2) well reasoned and supported by evidence but something that went against the mob mentality, or 3) just something that people didn’t understand and their gut reaction to it was negative.