This comes with using centralized stuff on the cryptocurrency world, be it exchanges or casinos in this case, which drives the "not your keys, not your coins" statement even further. In any case, I don't think this is going to cause massive waves in the crypto world as big as Stake is. Casinos are just a percentage of the whole industry and since it's a niche hobby the ones who are truly affected by this are just those that gamble. This will definitely cause some massive changes in the gambling industry paradigms though, the fact that such hackings prove that no hot wallet is safe if it's centralized, may inspire/encourage people to use their own wallets and only transact in exact amounts which is actually good.
Though, there is an clear advantage on hot wallets when comes to massive services which need to carter high volumes of Bitcoin. It is easier to make all automatically for small withdrawvals with relatively low risks; only big movements are managed by human beings and using cold wallets. You know, when whales decide to get their money off their favorite casino.
Also, concerning the centralized services, there is no a problem with them as they are careful enough to invest in their own security; I am also pro decentralization, but I doubt we will see a decentralized casino at the same level of Stake in the short term.