Earlier quoted context omitted.
Compile time never trumps best practice.
It's not "we need to keep compile time down to seconds, therefore configure in the source"; it's "compile time is seconds (if that), so there's not much difference between configuring in the source and configuring in a file except complexity". One part of the motivation for the best practice you cite is that compiling can be complicated and take a long time, and configuration changes should be quick. This is a solid…
> Because dwm is customized through editing its source code, it’s pointless to make binary packages of it. This keeps its userbase small and elitist. No novices asking stupid questions. There are some distributions that provide binary packages though.
source: http://dwm.suckless.org/