I suppose we will have to agree to disagree. If you have 2 identical twins who did say, Kyokushin; one studies only Kata/Bunkai for a year, and one only studies Kumite for a year. After a year they have a fight out in the car park... I know who my money would be on.
For pure combative ability I don't see that kata would add all that much useful for an MMA fighter.
I would differentiate between drills in arts like BJJ and Muay Thai and Kata in Karate I've seen. Drills in BJJ and Muay Thai are drilled to then be applied directly in sparring. Kata does not always teach things that can be applied in sparring.
Again, people involved in MMA aren't stupid and many of them have TMA backgrounds in some way shape or form. If full contact Karate or "old school" Karate really was all that and a bag of chips people would be using it in MMA instead of Muay Thai/Boxing. They aren't though.
The first full contact Karate guy who entered the UFC was Minoki Ichihara so far as I am aware. He was a Daido Juku fighter. Here's how he faired against Royce Gracie. At no point does Royce look like he was going to lose this fight:http://www.metacafe.com/watch/10006720/minoki_ichihara_vs_royce_gracie/
For people wanting to train in full contact fighting, MMA is a readily available option. I know you're passionate about your Karate Ken, but facts are facts. Full contact Karate is unlikely to produce as well rounded fighters as MMA is. If full contact or "old school" karate could produce well rounded full contact fighters, all the UFC champions would be Karate fighters and nothing else. We know they aren't.
I'm not suggesting Karate is a waste of time, but pining for a romanticised times when the common man quivered in terror at people who did Karate isn't useful or even necessarily accurate. Times have changed, people have more information about what is what and make choices accordingly.