[uses]

The thing about Krav Maga, Kung fu, or similar stuff that uses "deadly techniques", is that their efficacy is (conveniently?) unprovable. Meanwhile, submission grappling (such as jiu jitsu) and striking techniques (such as boxing & muay thai) are tested constantly from the lowest levels of beginners via sparring, to the highest levels of champions via competition.

Another thing to consider, is take a look at the all-around grappling skills of a top wrestler, judoka, bjj practitioner, etc. Do we really believe that their all-around skills wouldn't enable them to effectively use forbidden techniques such as ball punches or eye gouges or whatever? A skilled grappler is going to win a grappling contest, and a skilled striker will win a striking contest, regardless of the finishing techniques they employ.