Fair enough reply, but then how is Kickboxing different? Chuck Liddell and Overeem are many credited as Kickboxers and had to learn grappling just to avoid takedowns. Check out JDS, the guy is a boxer he had to learn BJJ but we never saw him using his ground game.
One art on it's own will never do well in MMA. Chuck already had an insanely strong wrestling base from college, that transferred defensively very well into MMA.
Chuck is more of a Karate guy anyways.
The main reason Karate is so disdained(i don't believe it is anymore, but for the sake of argument), I think, is that there are so many forms of it, and some extremely incompetent instructors out there in the 'mc dojos' where everyone gets a BB within a year, yet couldn't defend themselves from a paper bag.
Edit - Also, check out Michael "Venom" Page
, one of the most exciting Karate guys and prospects out there