>Nor can you reverse a transaction when someone steals your Bitcoins.
You're not always able to do that with the traditional banking system. Scammers were able to steal millions from corporations using wire transfers, and they weren't able to reverse them.
Exactly, you can't officially reverse wires. You can ask your bank nicely, and they can ask the receiving bank nicely, and if the money's still there, it may or may not be transferred back. But there is no official mechanism for reversing wires, and if the other side withdraws/spends the money before you start the process you're SOL.
But reversibility is provided by the intermediary, and isn't a property of the currency itself. For instance, if you're dealing in cash, there's zero reversibility. Likewise, I don't see the difference between a bank reversing a transaction for you, and the marketplace platform reversing the transaction for you.
