This is a fun game because it also is related to a lot of counterintuitive things about constraints and premature optimization. If you optimize something that

This is a fun game because it also is related to a lot of counterintuitive things about constraints and premature optimization. If you optimize something that isn't a constraint, the problem isn't just that you are wasting effort - it's that you might also be unwitting increasing the backlog of another part of the system. So it's not only "not helpful", it could sometimes even be harmful. That's why Goldratt et al emphasize constraint analysis so much - analyze the entire system (usually using causal analysis; why certain parts of the system explain other symptoms), identify the current core constraint, invest all spare efforts to alleviate that constraint only (and not other inefficiencies), and then re-analyze. I don't believe this is necessarily counter to Agile! It's just that a lot of people implement Agile badly. Which isn't a problem with Agile exactly, it's just that there's a lot about complex systems that are counterintuitive. You can't really be reductionist about it.