Tactics and situations change, the delivery system doesn't. Relying on a single art for self-defence is very much the act of a gambling man. Surely since self-defence would be higher risk, it would make more sense to cover all ranges rather than just training in one?
I believe many single arts cover enough of all of the ranges to cope with street self defense. For one the chances of your attacker being as well rounded as a mma are virtually zero and you can strike and gouge and do all of the wonderful things in the street that you cannot do in the ring or octagon.
Cheers
Sam:asian: