Gamblers are afraid that their personal information will become known to their relatives and everyone will know that they are losing money gambling.
Well for my view on KYC that you raised, I don't think that gamblers who dislike it are doing so because they don't wish their friends or relatives to know about their losses or profit. I think majority of it could be because the cryptocurrency system should be decentralised and everything about it encrypted. For example if playing with bitcoin as a decentralised cryptocurrency, while disclosing the identify behind it. That is the point and I think KYC goes against this principle of decentralisation which is the cardinal principle of cryptocurrency.
Everyone of us have a different perspective about KYC and we need to understand that there are some gamblers that see nothing wrong with KYC when gambling on a casino. KYC is not something we need to agitate on because even though we keep arguing about it, there are people that would always support the need for KYC on every casinos maybe for the reason of money laundry and scam attempt.
I really frown at KYC but what can we do if the casinos we are using start asking for KYC for us to gamble or use there casino.