Your original comment is somewhat unclear. Are you advocating for leaving old code in because the system works and it's more stable that way, or taking it out to force the necessary refactoring steps and understanding that will bring?
I'm sorry I wasn't clear: I re-read my comment and couldn't think of a decent edit.
It was the author whom I was quoting as saying "why would someone have old code lying around." It seems obvious why that's a good idea and it seems commenters in this thread (including you) agree with me and not the author.
