A court order won't work to reverse a transaction on the blockchain layer, only to force someone in-jurisdiction to send the funds back. That obviously can't be

A court order won't work to reverse a transaction on the blockchain layer, only to force someone in-jurisdiction to send the funds back. That obviously can't be helped, but having the irreversible transaction on the base layer still eliminates a whole class of issues that cost time and money to solve. The big chains really aren't susceptible to 51% attacks at this point. If one is really worried about it, you can just wait more blocks before considering the transaction finalized. The DAO fork is a different class of issue unrelated to 51% attacks. It's true that a group of people (minority or majority) can fork a chain with whatever rules they'd like, but this isn't going to happen because some company regrets some purchase they made, only systemic issues.