Yes to all of the above: proper technique is essential—so the technique works, so you use minimal effort in executing it, so you don't hurt yourself... all excellent reasons to do the thing right, hand techs as well as foot strikes, as Kacey notes. But kicks are special, in a very precise sense: because they entail that we balance our full body weight on at most one leg, they put demands on our ability to maintain our equilibrium in a rapidly changing physical situation which are extraordinary—especially when you take into account that of the three requirements for effective kicking, balance, power and accuracy, the last two are probably much easier to approach directly than the first. Very few ordinary components of everyday life stress our balance skills in a way even remotely like what we routinely try to accomplish in our dojang kick training.
I see in my own students how the lack of balance skills leads to sloppiness and poor conceptualization of kicks as weapons. A good chamber, a powerful thrusting strike, a high level of accuracy in the kick, all demand disciplined, repetitive and basically tedious work on balance training. I'm not talking about head-height rear-leg thrusting side kicks; I love the ways these look but I don't regard them as bankable techs for realistic street defense; nonetheless, they're great training tools. But with beginners, even a simple four-step front snap kick—chamber, snap out, snap back to the chambered position, and return—where you can freeze the kick at any point and hold that position indefinitely, is a major challenge. If they don't have enough control to do that, then there's not a whole lot of leg technique that they can learn until they've worked that one out. That's the reason I've become a bit compulsive over the years about decomposing leg tech training into basic skill components—train the chamber, train the pivot, train the slow extension into fully extended position, held for a full minute if possible, train rapid return to neutral fighting sance, train very rapid movement to close the distance on the attacker—because all those things have to work together seemlessly if a useful defensive weapon is going to result....
