Splintert, you forgot the fundamental starting point.
We want to avoid people using robbing as the best excuse to random.
I think it is settled that asking for all the gold inevitable ends up in someone dying.
Now, who says only peasants will get robbed? How will you prevent an epidemic of "legal" randomers saying "give me everything you have or die" to anyone they want to random?
People already use robbing as an excuse for randoming. They count on the victim not being willing to pay, since most people prefer death to paying 500g. Now give them the possibility to as for everything to anyone and they have the card to kill anyone they want.
By the way, the only thing I do when I play PW nowadays is to RP a bandit. At some point, the gang (Ahkmed, Robert Thompson, Sister Onward, Mario, etc. and me), decided we would specialize in tin cans. We opened quite a few. So I am not claiming to be a saint.