The ETH/ETC fork essentially reversed a month old transaction. It's not Bitcoin, but they still have a 1/2 marketcap. If the value comes from irreversibility, their marketcap should be almost 0. [Moreover, ETC is the irreversible chain and the value is 1/30 of the value of ETH.]
First of all, both ETH and ETC are irreversible. If someone tried to reverse something on the ETH or ETC chain, there would be another fork and there would be 3 Ethereum chains.
Also, the ETH/ETC fork did not technically reverse anything. The fork allowed the inclusion of an "irregular" transaction that moved funds from the DAO account to a "Withdraw" account.
I know, but why I useful an immutable log if nobody looks at it?
They used a magic fork to create the irregular transaction. They could have removed the original transaction and use the magic to declare the intermediate has valid. (I've seen this "solution" in discussions about what to do if someone puts illegal content in the blockchain.)
