Real fights are sloppy
Real fights are not choreographed like fights in movies, nor are the combatants limited to a certain set of techniques as they are in sporting matches. Real fights are not visually pleasing; they are sloppy and crude affairs. The more complex a technique, the greater the chance of it failing in a real situation. In addition, the effects of the adrenaline surge you will experience in a real fight will greatly reduce your ability to perform complex tasks.
Most fights are decided by blows to the head
Fights are most often decided by who lands the first solid blow to the head. However, successful head strikes are difficult since the head is mobile and difficult to hit and the bones of the skull are denser than the bones of the hand, so striking the skull with a fist may well result in a broken hand.
High and middle kicks are usually ineffective
In sparring, a high kick that misses or is blocked is not a big deal. In a fight, it may lead to your defeat or death. As soon as you take a foot off the floor, you are unable to move and are easy to unbalance. The higher you lift your foot, the more vulnerable you are. Low kicks are more difficult to block, they do not have as far to travel, and the chance of the kicking leg being caught is greatly reduced.