His later points are pretty Apache-specific, but most of the early stuff (if-else, variables, case sensitivity, and so on) are all symptoms of trying to produce an ad hoc implementation of a general coding problem-- config file parsing-- instead of doing it just once in a library.
This problem is *everywhere*. Why are we still putting up with differently-designed config files for your webserver, your ftp server, your mailserver, your nameserver and heaven knows what else, all supported by their own pieces of custom code which, like Apache's, each have the possibility of growing up to be subtly wrong?
I know the Windows idea of a centralised registry sucks in too many ways (inscrutable binary is no match for human-readable text files), but there's one thing it's got right: all the apps which access their configuration use a consistent API to do so. Is it an impossible dream to hope that someone gets a bunch of large free software projects to agree on what needs to go into a libconfigparse, then implements it, and provides bindings for major languages? Then we might stand a chance of avoiding weird config file problems cropping up in Apache and everywhere else, slightly differently each time.