An educative reply is easier to ignore than a (or multiple) replies in which you're ridiculed.
Moreover, being thought about how you're wrong about X might not necessarily translate in the subject being more careful before confidently expressing themselves on a Y topic on which they don't know anything about. Hopefully, ridiculing might make the subject reconsider that part of their character.
That said, the HN policies recommend to "be kind"... I have no idea how to "ridicule someone's post in a kind way" ¯\_(ツ)_/¯
I don’t think I see the same pile of downvotes that you’re seeing? My comment of ridicule got +10 votes in 15 minutes before I edited it, and now is down to +9 an hour after editing the ridicule out.
I see that “Calm down. It's a common misconception” did get downvoted.
Moreover, being thought about how you're wrong about X might not necessarily translate in the subject being more careful before confidently expressing themselves on a Y topic on which they don't know anything about. Hopefully, ridiculing might make the subject reconsider that part of their character.
That said, the HN policies recommend to "be kind"... I have no idea how to "ridicule someone's post in a kind way" ¯\_(ツ)_/¯