"There are a lot of obvious benefits to making software configurable, and these benefits are plain to all."

I must no longer be part of all. There are many websites that offer little configuration and work just fine for the vast majority of users (look I'm on one now!).

I've worked on enough projects to know that users will always want to be greeted by LOLcats instead of "Welcome to boring-corporate-system" or be able to change the background to lime-green. Focus on making a system usable from the get go, instead of letting each person craft usability out of a tangled web of configurations.

Configurable settings are like diamonds and herpes - they are forever.