Well, on top of everything that's being said here, one thing that strikes me is that this "calculation" omits that technical debt has value. I consider myself

Well, on top of everything that's being said here, one thing that strikes me is that this "calculation" omits that technical debt has value. I consider myself a pretty ok developer, in the sense that most of my time is employed at re-writing systems that have been written poorly by employees. So instead of writing new a shiny software, my valuable time is spent replacing something existing with something else. Zero value? Not quite! The first-written system has 2 objectives: 1. getting something out to validate the business model quickly - 2. Refine requirements following business needs. Point 1 implies that for the original system: the sooner the better. Definitely at the expense of quality. Point 2 implies that the system will experience incremental engineering, often leading to messy code. But, the market will be validated and the requirements refined. That definitely has a cost, happily paid by technological debt. That's actually why it's called technological debt!