try some of the 3rd party tools to change prefs....or CLI the change permanently. i heartily recommend you ask over at afp548.com.
until this last ubuntu+beryl combo, i considered mac os x "unix for the desktop done right". OS for consumer use should not be designed by committee, and when it's not...well, you get your unhappyness w/ the margins. i'm willing to bet 98% of users don't notice or care.
you misspelled "98% of mac users don't realize what's missing, they just know their document keeps printing out all fucked up."
that was certainly the case with my girlfriend, whose mac and whose document led me to this discovery in the first place. (and honestly, the Mac GUI feels like it WAS "designed by committee" to me. inconsistent as HELL. I'm reminded of the line from Bull Durham - "he fucks like he pitches - kinda all over the place.")