Not all "traditional" martial arts emphasize flashy high kicks or going to the ground as a primary method of defense.
The one I study has kicks but in 500+ techniques/variations I can count on the fingers of one hand the number of kicks that go above groin or gut level. If they're aimed at the ribs or above, it's almost always after the opponent is bent over (assuming he reacts as expected to the previous strike - never a given!) or on the ground himself.
High kicks look great in the air without an adversary or with a training partner who is allowing you to execute them for practice, and in a controlled environment where the footing is relatively stable and sure. But "out there"? Fuhgeddaboudit. Too much risk of losing your footing or balance or finding out that your opponent is quick enough to get a shot in at your exposed groin area.
As far as ground fighting we are taught what to do should we end up down there - because a good percentage of fights do end up that way - but the emphasis is on keeping one's own feet or getting back on them pronto if at all possible. If anybody goes down it oughta be the other guy.
Probably the most important thing to remember no matter what style of self defense you favor is the old familiar bit of combat wisdom: no plan of action ever survives first contact with the enemy. The key is not so much in knowing choreographed techniques - no matter how many or few, complicated or simple - but in having put enough options into your muscle memory through training to be able to react appropriately to whatever comes at you.