Your post is a logical fallacy. The fact that a bad metric exists does not mean all metrics are bad. Yes. That was, to some extent, my point :-) That and the

Your post is a logical fallacy. The fact that a bad metric exists does not mean all metrics are bad. Yes. That was, to some extent, my point :-) That and the fact that many HN folk will have encountered management doing dumb things like equating velocity or cycle time or lines of code with productivity. Which may explain their aversion to simplistic metrics like this. To address your specific fallacy, the output of coding is heterogeneous while the output of teaching is homogeneous. If I code today, it's a realtime optimization system. Tomorrow it might be a search product. When I taught, the output was always the same: students who understand calculus. Really? I can easily see it from the opposite point of view. When I code I'm just delivering running-tested-features. When I teach (which I have done, and still do) every student is different - they often start from radically different positions of attitude, aptitude and existing knowledge.