> Is all content in HN supposed to be professional and serious
No
> are humorous comments in fact allowed
Yes
Neither is what's going on here. It's reckless to share stuff you haven't even looked at yourself, that's fairly basic thing to care about. Sharing "here's a bunch of random GitHub repositories" isn't humor (I think?) nor would it been different if the text was "more professional and serious", whatever that means.
Why you so mad about someone trying to help others from getting hacked? Install all extensions you want, based on what someone recommend or what you find randomly on YouTube, but let others be educated about what that means for their own security, not sure who that hurts and why you'd wanna stop it.
I found it quite funny that people develop extensions that track the availability of one of the most important building blocks of the software industry, because their reliability is so poor.
You could have posted a warning to not actually install random extensions. Instead you came across as questioning why anyone would post links to them at all. The poster was clear they didn't actually recommend the extensions. Sharing stuff is fun, and hardly any software posted to HN is professionally reviewed beforehand anyway.