Kick Drills

I once had a terrific boss who taught me a lot not only about work, but life. One thing he taught me and that I've lived by ever since is to constantly ask yourself "Does what I'm doing make sense?" Applying that question to kicking drills has made me wonder. I have read more than once that (other than in breaststroke) kicking a) is used to maintain your body's position in the water, b) that you derive little or no propulsion from it (other than perhaps when sprinting), c) kicking hard can actually increase your drag and slow you down, and d) kicking hard more than doubles your energy use. Given those four things, I'd like to know your thoughts (and not just knee-jerk reactions) from both swimmers and coaches, regardless of your experience level: Does it make sense for us to use a large part of our practice time and energy doing kicking drills? Do we derive any real benefit from doing so? Do we do it because it actually helps us be better swimmers (which would make sense), or do we do it because "that's the way it's always been done" (which makes no sense at all). Keep on strokin'!