Shamefully, as an Apple employee working on Finder/Spotlight/Time Machine and more, I never, ever used XCode. Almost no one on our team did. We all used a combination of the terminal, our text editor of choice and command line tools to wrangle together binaries for local development. The actual production build was done by the internal build system which also used various scripts. Why didn't we use XCode? Take the same reasons stated today and apply them to 2001, 2002, 2003, etc. etc. etc.