To begin with, I am just analyzing the relative merit of martial arts as physical education. I’m not talking style vs style.
Right off the bat, I think karate is great for the youth. It not only teaches them how to punch and kick really hard, but teaches them how to stand up for themselves, believe in themselves, and never quit. These are all valuable qualities in life.
There is a lot of good karate out there but there is also a lot of fake karate out there. Remember what Mas Oyama once said, ‘without sparring, karate is essentially a kind of gymnastics.’
I don’t think MMA is good for people, young people in general. It teaches them all of the bad qualities of man and none of the good. I would go further, but I won’t, because I know people who train and teach MMA.
Aikido is a special martial art. It is ideally suited to physical education, and it teaches defensive principles. Aikido is essentially a stylized version of weapons grappling, wrestling with weapons. It is useful for police and military, and for people who aren’t fast and aggressive enough for karate, kickboxing, and MMA.
Also, weapons martial arts like Kali and Escrima are very good. These are the best for military training.
Whether you do karate, MMA, aikido, judo, or weapons training doesn’t matter, as long as you learn the principle of self control and self restraint. In the end, karate and hatha yoga has the same end, more mastery over the self.
But in the west, hatha yoga is seen as being for girls, since they are more flexible and peaceful to begin with. Martial arts training is the un-learning of violence, not the fostering of more violence and aggression and ego.
Once you can do the technique with skill and grace and effortlessness, then you are the expert. Sports are about winning and losing, but in objective reality, there is only the living and the dead. And it’s always preferable to be alive than to be dead.