It's wild to me that when I think MS I think this article, Vista, Windows Phone, Zune, Metro, ads in the start menu, the pleated pants meme and so-on, but I have coworkers that are total evangelists for MS technologies and platforms. Clearly a lot of devs get value from the ecosystem.
Instead of a single config dir where you just deploy the configs and you are done, IIS settings were all over the registry. And don't forget component registration - a single, global registry per machine, used by IIS. Want to run staging and dev server on same machine? Tough luck. Random software installs can upgrade components and cause failures in completely unrelated failures...