Grappling vs. The High Kick

This video demonstrates Aikido defenses vs. Tae Kwon Do kicking techniques. Back in my old TKD days, everybody used to say "Hey! You can't grab my leg"! This grabbing the leg was usually done by a beginning or mid-level student that is overwhelmed by the superior kicking of a high-ranked student or instructor. It is done instinctivly and without effort. That is why relying on high, long-range kicks SUCKS for a real fight. Anytime you extend your limbs too far beyond your core area you risk being taken off balence, thrown to the ground and could potentially have your leg damaged.
This isn't to say that a kick to the head isn't a powerful finishing technique, but it should never, never be used as a lead-in strategy. I read something by a Vietnamese martial artist who was very small in stature. He said "When you want to chop a big tree down, you don't start at the top". In other words, take out the base at the knee, shin, stomp to the ankle or instep. I have come to favor the Wing Chun "toes out" low stomping kick to the shin and knee. You can face centerline-to-centerline, allowing you to fight with either arm or leg. It does require you to be in closer, but you can avoid the long, reaching overcommitment of high side and round kicks.