I've referred to this comment a couple of times in discussions with people I've worked with. It is a great example for many problems of old code bases.
I was going to share this myself. It's really great knowing that it stuck a chord with others.
So much to takeaway from that post. For me it is
1. Its important how you structure your code (flags and global state can wreak havoc on a program)
2. No matter how bad your code base is - it can at least be functional if you have good testing
That comment still gives me nightmares. But also makes me really glad I don't work on such a codebase. Ours has some history to it, and a few areas that are a bit gnarly, but even they sound idilic in comparison.
I've referred to this comment a couple of times in discussions with people I've worked with. It is a great example for many problems of old code bases.