I find myself becoming my worst self on here, whether I want to or not, in reaction to others being their worst selves too. It's difficult to rise above the fray. Dang must have infinite patience, but I don't, and most people don't seem to either. Dang sets an example that few are willing to follow. I also feel that he gives people way too much lenience. It's like, "I see you've violated the guidelines badly multiple times lately. That's not cool. If you don't stop, then I might have to ban you, someday in the future, or maybe not. I'll give you one... hundred more chances." I'm exaggerating here, but only slightly. ;-)
I know that some commenters think that HN is great place for intelligent, friendly discussion. I personally don't understand that. It's like we live in different worlds. But I'm certainly not alone in seeing HN as "toxic", something mentioned in the linked article, as well as by people I know elsewhere. I come here for the topics, which are often very interesting to me, yet all too often I come away from HN regretting my participation. Maybe this is just a bad habit that needs breaking. :-)
This is one of the few sites that lets you say what you want to say and not think about it further. If I see something worthy of a response that might turn heated, I add my comment and don't return to the discussion. Other sites use notifications that force you to read responses to your comments.
Cuturally, for me, losing my cool is a sign that you've been beaten. I do my best to stay in control all the time - though there are inevitably times that what I'm trying to say doesn't translate into what I type.