The primary reason why that does not apply here is because nobody is selling "the market at large" to you as a cryptographically-secure decentralized consensus system. And besides, those ledgers are edited all the time by Authorities; it's irrelevant to this topic.

Edit: you are attempting to reason by analogy about a pricing system, and then trying to apply it to proof-of-work consensus? May I ask why?

But they're not keeping consensus ledgers for limited supply cryptocurrencies. Any of these failures or faults can allow a coin to be spent twice (or other mutually excluded transaction) with parties that have different views of the system, the result-- and any transaction which is casually depended on the conflict-- can never be part of a common system.

So it's like someone manipulates the market economy to convince you to buy a cheeseburger most other parties think they sold to someone else, and now your hand cannot interact with your neighbor's door because your hand contains atoms that-- as far as your neighbor's door is concerned-- aren't part of your hand but are instead part of my foot.

Markets are a tool. They have their applications and limitations, building the security of a cryptocurrency in an adversarial environment out of them sounds like a plan for failure. No less than using a cryptosystem in a place where you really needed a market may not give great results.

But you don't have to take my word for it, the prior consensus model in Stellar _already_ faulted, all on its own when, the requirement for the trust topology was violated. This fault wasn't a surprise, I (and others) called it out years before-- but the vulnerability of the system was publicly ignored by Stellar's creators while they ran Ripple and Stellar's advisers (including Mazieres, who was an adviser listed on the Stellar site on day one) even as they facilitated the sale of their ripple-reboot asset to the general public. It was not acknowledged until it knocked their system out. The improved consensus may better confines the failure domain, but retains the property that the safety of the consensus is largely external and depends on particular topological constraints without a procedure that provides any assurance the constraints are likely to be met.

Another response to me argues that it will probably be fine; but this flys in the face of reason. The same property existed before and it demonstratively wasn't fine.

If you look at the old BCT thread, I was a big fan of the original ripple IOU system, before ripple labs bought the name, and had recommended it as a potentially fruitful area to many people. The original system could potentially have been implemented without any global consensus at all, which was a large part of why I found it interesting-- Global consensus is enormously costly. But functionality like a new cryptocurrency currency for the purpose of funding the company and the integrated non-interactive rippling (which apparently has been largely turned off in ripple now due to other security vulnerabilities) brought back in the global consensus requirement. (The result was that I felt I had to go edit all my old posts to remove my recommendations, since the system was wildly changed to be something else)