The guy who wrote this did a talk about it, this website was to list sources etc. I’m an OpenBSD user and I did not personally feel like he had an axe to grind, and overall thought he was fair and had well made points. I’ll be the first to admit a lot of what he said was rather too technical for me, but if I’m remembering correctly I never saw many counter points to his claims.

I personally feel that OpenBSD is more secure for my use case, but I’m happy that people bring up points like this as humans make mistakes and not even OpenBSD is perfect.