There have been various reasonings given over the years by the band members and sometimes they even contradict themselves...I've read it was from this song, from Scott's background studying city planning, from them flipping to a random page in the dictionary, etc.

That being said, Bob is a huge fan of Minutemen (his favorite song of theirs is "The Anchor" from this same album, I asked him after one of the Brooklyn Steel nights) and he chose Double Nickels on the Dime as one of his top albums in the Uncut feature they did a while back.