> Writing comments explaining your motivation

This. Comments saying what you are doing is a code smell - not always wrong, but always worth a second look as to why the code wasn't clear by itself. Comments saying WHY code just did something are great because they convey the real info future me will need.

Despite the quoted statement, the article proceeds to give assertions/comments that don't fulfil that purpose. Assertions are fine, but (unless I misread) this is solving a different problem than good comments solve.