I saw this on Quora a while ago, and have been meaning to share it:
Software is one of the very few things where yesterday’s work output is most of today’s raw material. If you dig one ditch poorly, so what? You move on. But you can’t move on from a bad night’s coding. Your mistakes stick with you until you clean them up. Most people don’t, which is why a lot of software projects are a morass of bugs, messy code, and chaos, yielding low productivity and terrible morale.
-William Pietri on Quora
It’s good food for thought about technical debt. It doesn’t always make business-sense to go spend the time to clean up all the technical debt right away, but sooner or later it catches up with you if you continue to work on the same code-base.