If a site keeps doing that, competent people go elsewhere. Why is that post the top comment on an interesting paper from MIT?

Being inflexibly and uniformly critical of all ignorance also drives people off. And the direct subject to a reply isn’t always the most important audience. Sometimes you’re persuading people who are passively reading along. If that sounds absurd in this scenario, consider the number of times a gentler rebuttal in a discussion has given you pause to reconsider some foolish idea you hadn’t expressed. If you can’t think of one, you’re either an outlier genius or maybe overconfident and overcompensating.

Either way, most people aren’t dissuaded of their ignorance by being chastised for it. Speaking as someone who’s lost important friends learning that the hard way.