Ummm...no. It is exactly what I teach, and I teach it for a reason. Head kicks are nice and flashy and showy and great for practicing technique, but they are not practical for self defense. Your balance is better and your kicks are stronger if you keep them at the belt line or lower.
You may teach it, but that doesn't mean it's not urban myth. If you can kick high effectively in sparring, you can do it in a self defense situation. High kicks may very well not be your 'go to' kick in either situation, but that doesn't mean they're ineffective or impractical.