The essence of software engineering, in my opinion, can be captured in two words: managing complexity.
Instead of hunting down code smells, we'll search for smells coming from our mental processes. If we expect our code to be clean, we should start with our own mental hygiene.
Just as unclean, untested code can create technical debt . . . the unclean workaday habits can lead to micro level technical debt that drags down the cognitive ability of the individual engineer.