If somebody thinks they can ignore kicks in their martial art, they are in big trouble!! I don't believe spontaneous improvised Aikido techniques are going to do anything but open you up to a butt whipping. You have to train realistically against them and build your techniques. They are fast, and they are powerful when fired off by somebody who has been doing them for a long long time.
Underestimating kicks is the same as someone dismissing Aikido as a dance. Just plain ignorant. They can break your leg, knees, wrists, arms, head so it's probably a good idea to learn something about them.
Here is some Muay Thai clips of Ramon Dekker. Go to a Muay Thai camp and do some traning. Your respect for kicks and punches will increase dramatically.
http://www.compfused.com/directlink/442/
http://www.mikemiles.com/video/dekkerpena.mpg
http://www.mikemiles.com/video/dekkersaengtiennoi.mpg