He's playing something that looks vaguely like an acoustic guitar. Therefore in the eyes, ears and minds of the general music industry and media - especially in the USA - it's categorised as "folk". We are long past the point where this (ab)usage can be corrected. That's why it's best to not use the term at all. You can say it's not traditional music with more certainty though.

(It's not that extreme either, just standard rock muso noodling Try listening to Michael Chapman's "The Ressurection And Revenge Of Clayton Peacock" if you want something more adventurous)