His podcast is also one of the top downloaded worldwide and has been for years.
Nobody expects for example americans to know some french or spanish comedians/hosts, and HN is predominantly american website.
He seems interesting but the lengths of podcasts mentioned in the article are showstoppers for me - I can't imagine dedicating 3-5 hours to this (and I can't properly listen to such conversation and do something else). That said, I got motivated to watch the Musk part, mainly for the Musk himself.
The article, albeit with its flaws, mentions interesting point - his popularity being the result of these uber-politically-correct days, where masculinity is often frowned upon, and white western guy should feel guilty for being who he is/was and keep apologizing (I am not western and not american so this is a foreign feeling to me, but I get where it comes from). Every action makes reaction, a nice example of this general principle.
I personally only listen to the episodes where I have an interest in the topics or the guests themselves i.e. the intellectuals, nutritionists, incredible athletes, and scientists. In this way I use the podcast as more of a medium to experience the guests rather than listening for Rogan himself (although I do appreciate his generally progressive views and genuine intellectual curiosity). Even if I tried I can't imagine devoting 3+ hours to a comedian or MMA fighter talking about whatever.
I think the author touches on this in the article, the audiences of the podcast are quite diverse and many are only interested in a subset of the content. The diversity and neutrality of Rogan allows it to act as a neutral medium to be exposed to an in-depth view of a variety of topics and people that you would not have the opportunity to experience otherwise.