I actually don't think this is the right move. Any investor should know that there is no guaranteed investment regardless of asset class. You can lose money at any time. These particular investors on GDAX even invested with margin meaning they borrowed money to increase their leverage to increase their returns. This is a highly speculative and risky move. The investors who did this should have understood the risk they took in doing this.

However, I do believe that exchanges should compensate or potentially bailout clients if they are at fault. For example, if an exchange goes down during a day, a trader or investor can't do any transactions in their position leading to potential losses. In this case, I believe the exchange owes something to their clients.