It wouldn't be so complicated if there was only 1 way to build a server. Unfortunately, there are multiple Operating Systems that can run a server such as Windows XP, Vista, 7, Server 2000, 2003, 2008, Home, Professional, Enterprise, etc and various flavors of Linux. None of the setups for those OSs are going to be exactly the same and it would be nearly impossible to keep a current guide for all of them. Not to mention that there are multiple versions of Perl, MySQL, and VS that can be installed which can require different steps. Much of that stuff is constantly evolving, so keeping a current and accurate setup guide is not as easy as it may seem.
Most of the more recent guides are accurate enough to get the information that is needed to get a setup working correctly. The server code itself could probably be rewritten to allow for easier setups and to make it more flexible, but that would probably take a considerable effort and I haven't seen a ton of interest from anyone wanting to do it.
Luckily, every year or 2, someone spends the time needed to write up a new complete guide. Though, if they are not written in the wiki, it makes them much harder to keep updated. Anyone can make their own Wiki account and update/edit the wiki though, and it is a community effort so feel free to work on something if you are interested and time permits