The reasons for the diverse nature of the documentation are several. Off the top of my head I can think of these:
1. The participants are doing this of their own free will. If someone gets a hair up his ass and decides that an install step-by-step for Red Hat version 6.2 as installed by a left handed Czechoslovakian woman with a bad lisp on Thursday is needed he will write it and post it. If the Dev team decides that he did a good job it will be cannonized in a file somewhere in the CVS. Depending on how they feel that day and how much time they have, other files with which it conflicts or which it superceeds may or may not be updated or replaced.
2. As referenced in reason 1 above there are an almost limitless number of possibilities for the initial state of the Linux box on which the software is to be installed.
3. The initial charter of the project was not to bring SEQ to the masses, but rather to make a tool available to those who demonstrated a rudimentary ability to solve problems and to interact successfully in a social context of geeks. The underlying concept being that those people would be less likely to do stupid things in game that would draw attention to the fact that they were using SEQ and thus cause SOE to divert resources toward thwarting the project.
4. This is not the software that runs the 911 system. It is a tool to make a game more playable. You can't blame people if they do not want to spend 40 hours of time that they could otherwise devote to friends, family, AA exp, drug abuse, self abuse......etc to writing a step by step guide to something that they figured out for themselves.