This is an excellent example of why comments in code are so very useful, helpful and in my opinion, necessary. ... nobody at Microsoft ever understood how the code worked (much less still understood it), and that most of the code was completely uncommented, we simply couldn't figure out why the collision detector was not working. Heck, we couldn't even find the collision detector! To all those folks out there who kee…
Heck, we couldn't even find the collision detector!
This sentence tells me that the big problem here comes from the latter, much worse, source of of readability problems. The fact that they couldn't find the collision detector implies that the code had no class named CollisionDetector, no procedure named DetectCollisions, nothing of the sort. Which implies (if not conclusively) that there was a whole lot spaghetti code floating around in there. Or at least a whole lot of very poorly-factored code.
I do think that comments are an important part of making code readable and maintainable. But comments are there to handle less drastic readability concerns. Documenting what units a parameter should be in, for example, or saying, "The following code implements X algorithm with Y and Z optimizations applied." Comments should never just be a substitute for using language-level code organizational and structuring constructs to organize and structure one's code.