Everyone should take this occurrence as a learning experience about what happens when a coin forks and an exchange does not know about it...or in c-cex's case they thought they were updating to the right version due to an outdated thread.
Unfortunately the responsibility of that oversight is the cost of doing business as an exchange. I feel an exchange has the responsibility to ensure they are on the right blockchain for any coin they support. Checks and balances need to be in place to verify they are on the right blockchain. The reason the loss is so large is due to the length of time they spent on the wrong blockchain.
C-Cex asking the devs to cover THEIR losses is them mitigating those losses. I suppose it's worth a shot for them to try. The scarier part is that the devs are actually entertaining the thought.