I think you’re right, programmers (and people) can be blinded by rules. Knuth never meant to suggest people should use the least performant solution available.

I think you’re right, programmers (and people) can be blinded by rules. Knuth never meant to suggest people should use the least performant solution available. He’d be horrified by some of the things people justify with his quote. The idea was always to make good engineering choices from the start, including using tools and techniques that are known to give good performance, but to wait to get low-level and measure and count cycles until the code is mostly done being written and not going to change significantly later. Choosing a less performant option because it’s slower is a bad choice. Choosing a slower option that is easier to refactor as you go, when it’s clear refactoring will happen, over a faster solution that will make refactoring harder, that is a perfectly acceptable engineering decision.