I think that if you consider that the chance of a threat to cause a given amount of disutility being valid is a function of the amount of disutility then the problem mostly goes away. That is, in my experience any threat to cause me X units of disutility where X is beyond some threshold is less than 1⁄10 as credible as a threat to cause me 1 unit of disutility. If someone threatened to kill another person unless I gave them $5000 I would be worried. If they threatened to kill 10 poeple I would be very slightly less worried. If they threatened to kill 1000 people I would be roughly 10 times less worried. If they threatened to kill 1,000,000 people I wouldn’t pay any attention at all. Taking these data points and extrapolating I form the heuristic that the chance of someone threatening me with X units of disutility over a threshold based on how much they are demanding and whether I can fulfill that demand decreases faster than linearly.
[i]Nothing could possibly be that weak.[/i]
On the contrary, I think it is not only that weak but actually far weaker. If you are willing to consider the existance of things like 3^^^3 units of disutility without considering the existence of chances like 1/4^^^4 then I believe that is the problem that is causing you so much trouble.
I expect that many people who grew up to be scientists and mathematicians attempted to create famous proofs when they were young, but I also expect that for many engineers such as myself our youthful folly went more along the direction of perpetual motion machines. I’d actually like to see some research on what the correlations really are.