Of course it's deeply patronizing. It carries the presumption that you and nobody else is the Educator of Audiences and the Guardian of Validity of Discourse. Even if it might have an element of truth in a particular conversation, flaunting it (or just believing it) is a sign of profound social ineptitude.
What the hell? It carries the presumption that you have something educational to say, but it certainly doesn't presume that the other person doesn't. Education can flow both ways. Indeed, it's more interesting that way.
Just look at any thread on this forum: people contribute information and correct each other and it's interesting, not patronizing.
I seriously doubt that in most social situations, HN-like discourse would be considered "interesting".
Geeks find the constant back-and-forth of corrections in dialogue to be interesting and educational. Non-geeks do not; they lose interest by about the second iteration, and will become annoyed shortly after.
The article is about actual conversations, not HN threads. Real life interactions have to do with whether the other party perceives you're being a patronizing git, not whether you believe you have something educational to say.
Little Edit: if you think describing 'I don't agree with you' as an 'altruistic desire to educate' and single-handedly preserving the 'validity of discourse' and the 'truth and correctness of human understanding of the world' is anything short of absurdly presumptuous, you might want to re-read the linked article very carefully.
