This reminds me when learning to write papers in college my professor would help proof my paper. I Had clarity in my thoughts but it didn’t translate to paper. We would evaluate the paper line by like. I would often use the phrase “X is better than Y”. He would stop me and ask, “why is X better?”, and I would give a more precise meaning.

I like how the author applies the same idea to “clean”. Rather than just blankety apply clean he suggested expounding on the reason why it’s cleaner.