[saurik]

That section is talking about miners, not exchanges; and it specifically notes the limitations and assumptions that even make that possible: in this case, that the Bitcoin proof of work is subject to acceleration using ASICs. Even then, that was a response to a specific attack: using >50% of the mining power to do a takeover of the blockchain, which was itself made more possible (as otherwise it would fizzle) using the takeover contract specified by Vitalik. It was an interesting analysis of a specific scenario that the model seems to provide protect against.

In the very different case of Bitcoin Cash, what you saw were miners perceiving segwit as a protocol fork which would devalue the future potential of their investment in specialized mining equipment, as it changes the proof-of-work parts of Bitcoin into a form of contract verification for payment channels rather than as the one true way a transaction can be performed, so we would have expected them to revolt to maintain the rules they had invested assuming (and in fact once they were already dealing with a fork, they went ahead and made their own rule changes to benefit them: larger blocks).

[paulgb]

Fair point, the example of BCH may not have been a good one. I stand by my more general point that grim trigger isn't a strong incentive in crypto because a rational, selfish player can profit from pulling the trigger.