>I wanted to talk about its garbage collector (1, 2), its cooperative scheduler that many people think is a preemptive scheduler, its very loose approach to correctness… and he didn't want to talk about any of that.

This is not the way an emotionally intelligent person approaches a conversation. The idea that a conversation should be a demonstration of ones own knowledge is a pretty common notion I see with socially-stunted geek types. Growing up with a narrow or minimal social group will do that, it's no one's fault, but it's a pretty clear indicator this person's advice on interpersonal relationships shouldn't be taken too seriously.

In the same way you can tell immediately from a blogpost that someone is an inexperienced engineer, the takeaway from this one for me is that the author is an inexperienced friend.