actually, with regards to GSP. if you look at his last few victories...they've come from his remarkable wrestling abilities.
what's ironic, is that he started working wrestling into his overall game.
look what he did against Penn this past weekend...he used boxing more as a setup to take Penn down and grind him down on the mat.
someone unfamiliar with his background watching him fight wouldn't even know he was a karate guy.
with regards to Machida, yes, he represents karate well...but he also had to augment his game by cross-training.
i do however agree with everyone's comments towards Rogan....
I agree with this for the most part. GSP has largely... I won't say abandoned, but definitely minimized the integration of his karate background. Outside of the occassional spinning back kick, GSP works a pretty good blend of western boxing, muay thai, wrestling and BJJ. He's still got the karate skills he first learned, but I'm not sure he trains much karate anymore, if at all.
Machida, while also having cross trained, has stayed far more faithful to a karate foundation (shotokan in his case, if IIRC). Machida is also very interested in cross training. He's a BJJ black belt and has trained everything from sumo to wrestling. But if you look at his fighting style, he still works the karate first and foremost.
Regarding Rogan's remark about Karate not having been successful, I think he's referring to some of the more "pure" karate guys. There's one in particular that comes to mind... a brutal knockout by Guillard over Rick Davis in UFC 60. Here's the video:
http://mmadepot.blogspot.com/2008/01/melvin-guillard-vs-rick-davis-ufc-60.html Bruce Buffer calls Davis a "Jiu Jitsu and Kickboxing fighter" but I'm pretty sure his training was largely karate.
As for the Rogan vocabulary, I don't have a problem with it. It's useful to have a vocabulary to describe certain moves and positions. For example, Rubber Guard as opposed to, "that position where he pulls his ankle up for control without relying on the gi." Like it or not, Bravo developed and refined a lot of those particular positions. He didn't invent them, per se, but he worked them with intention into a larger game. X Guard didn't really have a name until Marcelo Garcia created an entire strategy around the position. Same thing. But it's useful when someone's in the position to use the term X-guard because it's specific and meaningful.