Code suffers from the equivalent of metal fatigue. Every time you make a small change it is weakened and eventually you end up with a something that is more cracks than good metal. If you have a really good original design that's been scrupulously maintained despite the many calls for a quick fixes you can take out the components and replace them. Much more likely after a number of years is you find that the components have been repaired many times by welding them to the surrounding parts and using an angle-grinder to remove them is messier than undoing a few bolts with a spanner.
Premise of that article is that legacy code needs fixing. As Seven Smiles said that is often the case because of deadlines etc. (I would add developers expertise and experience as a big factor) But not neccesarily always true as stonec explained. In rf2 case code obviously needs fixing/rewrite. But that could also be a legacy of previous project/s. Anyway I would like to peek into rf2 codebase. Just curious.
...regardless of premise - the principle stands on its own. I could easily quote other sources in a different context, but I've made my point.
For Friday the 13th I was expecting something buggy but at least released. We are still talking about beta then any bugs are welcome.