I don't think they are scared but they are purely foe the privacy of their lives but they have to know that no casino is 100% privacy (no KYC) this days. They would say no KYC, yes when you win small amount they would not ask for the KYC but when you win big, they will ask you KYC and when a casino suspect an account, they would ask for KYC even though the money is small.
So you really have to expect that anytime a casino can demand KYC from its players. If we already have that mindset, then it won’t be surprising when it eventually happens.
As we know, KYC isn’t really initiated by casinos themselves, it’s pushed by governments. Because of that, rules can change, and in the future things will likely become even stricter. We might even reach a point where KYC is required before you can deposit. That’s probably the worst case we don’t want to see, but it’s still possible.