Interesting thread and replies. In the Hapkido I studied, we learned several low kicks. We attacked the thigh, knee, shin, but the knee and ankle mostly. We were not taught to be shy about attacking any part of the body that would achieve our purpose of defending ourselves. I never was taught to stomp the top of the foot. But I guess if you can do it successfully time after time, you should keep practicing it and use it.
I would say to those who disparage kicks to the legs, that they are like all other offense moves. You have to practice, practice, and practice more. Not only will you get better, and should be more proficient, but you will also learn what works best for you most of the time. Kicks to the thighs, knees, shins, and ankles can work and work well, causing great pain if not damage to an opponent.
In my case, I am not so good at inner thigh kicks. I am good at intercepting an incoming kick by stepping forward, putting my same leg as the kicker is using, in the crotch, grabbing his leg and pulling it back and in. If the opponent can't get up, he can't fight. But that is a bit different than most of what has been discussed.
But the other kicks I mentioned I can make work given the right circumstances provided by the attacker. That is also key to using low kicks.