This is a subject that, for me, is always fun to talk about. Now that I'm in my mid 40's, with 26 years of study, I have been able to truly embrace my base Okinawan style's strategy of closing distance and keeping kicks at waist level or below. While I still kick to the head while sparring or kickboxing, when I'm really working on self defense (aka kata bukai) all kicks are low.
When I close the distance with my opponent, the need for and practical use of high kicks is eliminated (especially since my knees no longer react well to jump and/or spinning techniques). The exciting thing is that when you stop looking up for a target (i.e. head) and look from the pelvis down, you find targets that are especially debilitating to your opponent. Additionally, by staying in close I find that my opponents ability to kick high on me (spinning or otherwise) is greatly reduced unless the person is an exceptionally gifted fighter.