There sometimes is a way to get it back though. If the hacker tries to cash out through an exchange he may be caught.

Serious question: is it illegal to exploit a cryptocurrency flaw for profit (strictly at the protocol level -- not hacking someone's machine or wallet, etc.)?

Or if the devs decide to just hard fork the money back.

as far as i know the recovery rate for stolen crypoto currencies is zero

The FBI has seized Bitcoin a few times. It's likely that stolen cryptocurrency will be recovered in the future because of chain analysis and exchanges like Coinbase that want to score points with regulators.

https://www.forbes.com/sites/kashmirhill/2013/10/04/fbi-silk...

that was a huge exceptional case. most thefts are smaller and don't attract much attention. anyone who is smart enough to steal a lot of coin is not gonna dump them on coinbase. They are more likely slowly tumble them and sell them offline or on small exchanges.

Small thefts of crypto are compareable to small theft of cash in the real world?

Exchanges have sometimes protected users from their exchange hacks. With varying success.

And wasn’t there a hard fork rollback for DAO?