Why do you link to a blog, rather than an introduction or a summary? Is this to test whether we find it so silly that we don't look for their best arguments?

My impression is that antinatalists are highly verbal people who base their idea of morality on how people speak about morality, ignoring how people act. They get the idea that morality is about assigning blame and so feel compelled only to worry about bad acts, thus becoming strict negative utilitarians or rights-deontologists with very strict and uncommon rights. I am not moved by such moralities.

Maybe some make more factual claims, eg, that most lives are net negative or that reflective life would regret itself. These seem obviously false, but I don't see that they matter. These arguments should not have much impact on the actions of the utilitarians that they seem aimed at. They should build a superhuman intelligence to answer these questions and implement the best course of action. If human lives are not worth living, then other lives may be. If no lives are worth living, then a superintelligence can arrange for no lives to be lead, while people evangelizing antinatalism aren't going to make a difference.

Incidentally, Eliezer sometimes seems to be an anti-human-natalist.