He was a software engineer at Netflix before turning to content creation. It is also clear watching his videos that he knows his thing. As an experienced programmer myself, I find his commentary to be way too relatable to be just bluff.

He may not be Don Knuth, Linus Torvalds, John Carmack or Fabrice Bellard. But he is definitely a serious programmer. That he livestreams doesn't make him less of a programmer.

It is clear watching his content that he just chases whatever the talk of the day is and chiming in on things he has no knowledge of.

Who cares what you think of someone else’s qualifications?

It’s just someone quoting someone to help ground their position.

What if it was a journalist writing about a security vulnerability then a programmer quoting them, would that count then?

If it doesn't matter, why did the previous poster mention them?

It's pretty clearly a type of argument called an "appeal to authority", where an authority is cited to add credibility to a position. It's usually considered a pretty weak form of argument, but it can be effective. So the credibility of the cited authority is relevant.