I think the argument for ETC is pretty simple. The hacker followed the rules. You don't reverse immutability on the main chain because someone fucked up a custom smart contract.

The same logic applies to privacy. You don't take away privacy because a small minority of people are going to use that privacy to break the law. The problems created by taking away privacy are far bigger than the ones that exist. Sometimes doing nothing is the smartest course of action.

That being said I think I would have been on team Ethereum over ETC if I had been around when it happened. Community consensus is the new law. We're forging the ability to bend or break the law for relevant exceptions. A middle ground needs to be forged because both sides of the spectrum have serious consequences.