I was just thinking the same thing... We have lines of commented out code from 1988 (yes. that is a correct date) that people flat out refuse to delete. I am so glad I got out of that mess...
In all fairness, I have had to touch somebody else's code on a few occasions where they did not use any kind of VCS, and I was very reluctant to flat out delete code, so I did the same thing described in the linked page - comment out the original code and add an explanation why I replaced or removed it, along with a date.
And when reading somebody else's code, I tend to appreciate if the code carries its history with it, at least to a degree. What I really do not like, though, is when there is a piece of commented-out code with no explanation of why it's there in the first place or why it was commented out.
