So far Craftymissbeth wins as the only possibly satisfying response that doesn't make me feel cheated.
I want to give credit where credit's due, so I want acknowledge my question as satisfactorily addressed by Crafty, with much respect for her answer. I was impressed.
But I'm still willing to address any other versions of justification for this policy, because...uh...clearly I have a passion for it.
[OMG the owner or moderator or someone (or maybe it was randomly generated??) made my avatar a snowman. This seriously cracked me up! It's perfect!]