I can respect some casino who adding required KYC before using their service. most likely about money laundry and legality for their customer. as we know some casino restricted some area for using their services. they didnt want their legality had problem because they didnt even know who using their service before hand . and also KYC in most gambling platform only formalities and they wont making harder registration for their new user.
I mean that would be the least that you can do when you are doing business, complying with the rules and laws that govern your business. I like the idea of KYC because it helps you not become a suspect of something bad in the casino because you know that you won't do wrong because they have your identification.