uhmmm this topic HAS been done to death. There are points on both sides, the whole Zen argument actually (even though it is SO trite) makes sense to me because of this:

riding w/o brakes forces someone to be more aware

awareness=mindfulness=zen

I, however, choose to ride w/ brakes b/c it lets me go faster and have more fun since I know I have the ability to control my bike. I still manage to stay aware somehow, imagine that.