as it's supposed to be Gangnam is a town in Korea which is pretty much California's Hollywood. It's full of phonies and posers and people just trying to sell out. Psy grabbed the obscurity by the horns and rubbed the ludicrousness in their faces. - You might notice that in the video, Psy is dressing and dancing all glamorous, but then finds himself in low budget and trashy places, like a barn, a sauna with old men, a parking garage, a toilet, etc.
His motto is "Dress classy, dance cheesy."
besides that, the song and dance are just catchy XD
i'd say most of the people who've seen the video miss the point completely. they either see the song as catchy and fun, or they write it off as being stupid and pointless. either way, Gangnam (and glamor in general) has been called out. now everything fancy and classy is just gonna remind everyone of riding a horse.