I don't know where you get your economics from, but what you're arguing amounts to saying that no one ever will just take a loss on anything.
If that's what you are reading then I have expressed myself poorly.
No rational actor with a classical monetary utility function will act to foreseeably incur catastrophic long term losses is about as close as I would come to that.
A miner would only rationally hold out for >$700 if he didn't anticipate needing liquidity prior to the expectation of that price arising. The marginal utility of dollars necessarily increases relative to Bitcoin if the miner has a pressing need for dollars.