A trend I've noticed the past couple years is that people make the excuse of "code should be self-documenting" so they don't need to add comments. But then very helpful contextual hints that are not otherwise documented anywhere, like the one you provided, are completely non-existent and the original dev has left the team, it's been 2-3 or more years since the last time someone touched it, etc.
Code should be self-documenting, don't get me wrong. But that's more in the vein of showing (what), not telling (why/how). There still needs some be some method of telling.
