In an actual "self-defense" situation, the majority of those strikes being attempted, will be a “round-house” punch, a “straight” (from the shoulder) punch, and an “upper-cut”. The only kicks that most are likely to encounter (from someone who isn't formally trained) is going to be a front kick, or (some form of) a “round-house” kick (seems that everybody, knows how to perform some manner of a round-house kick, LOL).
As for being considered a "good" choice for defensive purposes, I believe that they are not. My own "standards" (for students) are, that if a 95# female isn't able to make the technique work (on a 200# male), then the technique isn't worth teaching.
That standard (alone), means that 95% of the MMA (types of) techniques wouldn't qualify (to be taught in my classes). It also means that the systems that emphasize any manner of brute force tactics (alone) wouldn't either.