Maybe so. I think would be nice to have more this option to gamble with. Casinos accept many different currencies I think there isn't any problem by accepting Bitcoin Cash. As you said, the price must become more stable first, and I'm sure at some time it will happen. Surely not all casinos will start accepting it, one of the main casinos of Crypto-Currency world that I heared is thinking about adding this is SafeDice, good one.
Ya it is true that first it has to stable the price movement and after that only the casinos will try to use BCC but it will take time, and if the network of this coin is good then very soon we can see lot of users using BCC and other gambling sites will also start to implement on their site.