It's very much pop history. He's really not an academic and somewhat hides behind it.

A lot of the community are outright hostile about him to be honest. Largely because he likes getting into sweeping conversations about culture. The intro to his series on the Pacific Theater spends probably 20-30 minutes on his thoughts for why Japanese society was so fanatical and he uses some less than polite language to describe it.

Many online history communities tend to shun him because it's the 'internet' thing to do. My experience with the history department at my university was that anyone was happy when pop-history gets flipped into genuine academic interest. So if Carlin and his narrative style gets you curious about things, I'd say keep listening.