Nice write-up. The problem with the scenarios where someone steps up to rescue Bitcoin is that now they would basically own the ledger. If you can rescue it, implicitly, you can destroy it by not rescuing it. If bitcoin depends on, say Marathon continuing mining long enough to dump their bags, obviously it's a failure. I wrote more about this here: https://micah-warren.ghost.io/response-to-rob-warrens-2/

-Micah