And yet, judging by this thread, it's pretty easy find FTers who agree that broad generalizations aren't a very good way of deciding who to punish....

And even if you make it voluntary, I suspect most FTers won't be happy. Most airlines reserve seats up front for their elites, likely because most elites like to be able to get off first in the event of tight connections. I suspect you'd have some unhappy elites if they're told they have a choice of sitting in back or sitting in the kids' section up front...all based on your studies of airplane acoustics.