OP is short on reason and social skills, but I'll play Devil's Advocate here...

This word "zen" that gets tossed around, it means a very specific thing. Practicing zazen is about bringing the mind to a state of emptiness, so that reality is being experienced as such, directly, in every moment. This is found to an extent in the experience of riding fixed, and more so brakeless.

Riding brakeless requires stepping up one's game, not only in conditioning and bike handling but just as importantly in observation and decision making. Only in such a heightened state of awareness can a situation be encompassed and acted upon with unobstructed reflexes. I have yet to ride a velodrome but I'm guessing this is a large part of the appeal of track racing.

On the streets, going brakeless involves riding much more conservatively with much greater awareness. It's another kind of practice.

http://en.wikipedia.org/wiki/Shikantaza

I don't take nearly the same amount of risk as I do when the brake is available. I ride a smaller gear more slowly, maybe even walking the bike if circumstances dictate. In this way I'm safer without the brake. And technically speaking it's about the same as riding a coaster brake anyways.

Of course anyone that rides brakeless all out hard and fast is a dumbass, and they'll learn soon enough. Maybe if they actually spent some time sitting zazen they wouldn't behave so foolishly.