I've seen heaps of that -- spent much of the last 12-13 years as a trainer, and people can get precious about their manuals.
I love the fact that if someone works for a big company they are automatically assigned "expert" status -- like, "Yep, that's our model and it's correct because it was put together by a guy from [Insert name of big investment bank here]. Quick scan of the workbook shows that the user is limited to half a dozen functions and could have put together a much more efficient workbook if they knew a bit more about Excel.
Denis