It does matter -- he was one of the first "network developers". He published RFC 896 over 35 years ago; he has more experience on this topic than almost anyone.

> Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith.

This is not the strongest plausible interpretation of what he said --

He's not asking for people to not develop async code. He's asking for them to not hide it in synchronous code.

If you're expecting a blocking system call, and actually get a brand new background thread that's polling, it's quite reasonable to be frustrated.