thats because he either raced the bike or used it as a track bike.
Actually its so bolts don't back out in general and so Hose clamps don't come off. They have you safety wire anything of major importance, like brake caliper bolts which won't leak oil, but you'll loose braking ability. So its for safety in general. They even have you safety wire your clip type masterlinks on your chain so that you won't loose it either.JET said:jyeager is right, it is so bolts don't back out and leak fluid. Why do you think you only have to safety wire things to do with fluids? You don't have to safety wire body or frame bolts.