A few points Ken:
Why would people "fix" karate when MMA is so readily available now? If people want hard training, trying to re-invent the wheel in a Karate class would be much harder work that going "Screw this, lets go do MMA".
Second point would be that maybe there are a lot of people in Karate who like the JKF way of doing things. I've seen some serious injuries in Judo tournaments and with the MMA folks I've trained with. Trainined in hard, full contact systems takes a toll on people. Training in a light-contact system might be less likely to induce injuries. Some people might prefer that.
"Let your food be your medicine, and your medicine be your food"