Pointing out to someone that you don't share their worldview and in fact find it weird does contribute something, hopefully it pops their little bubble of thinking everyone agrees with them. And no, I didn't insult him, I said his reality tunnel is weird; that you can't tell the difference between insulting a person and commenting on their worldview says a lot about you. You can respect people without respecting their beliefs, you are not your beliefs, no ideas are beyond criticism.

Why shouldn't we insult myopic, damaging worldviews like the OP's?

You could, but you could also explain why they're myopic and damaging. I realize it's obvious to you but for the people in general the impression that it passes is that you don't have arguments and resort to name-calling. Seeing as you probably actually have good points to make, it's a shame that this is what transpires.

You shouldn't do it on HN, because it's noise rather than substantive discourse.

Because you all got trolled, which produces the most tedious kind of thread there is.