Of course they can, but it implies limitations for the business. A casino which doesn't adopt KYC procedure will be very limited inside the industry, because it won't be allowed in many countries where regulators enforce it to consider a business legit and legal. So they prefer to follow the legal requirements to be available to a larger public, to more potential customers. We can't blame casinos for that reason, after all they have to stay competitive and to seek for the ways disponible to them to increase their customers' base.
The casino without kyc had two way of face,one is to scam the people who deposit the money.They keep allow the gambler to play their website for the certain period of time.After reaching the good value,the casino will scam like the FTX exchange and fly with the deposit money and winning money of the gamblers.If the company is very big one,they will involve in gambling just for the hobby.To keep their money source accountable,the casino will run the just for the accountable.This also reason for the casino to make allow the gamblers to do the casino without the kyc.
To not demand KYC doesn't mean the casino is going to scam customers. Freebitco.in is working since 2013 and has never asked for KYC from gamblers. Moreover, even unregulated casinos can operate honestly for long periods of time without any problems for customers, while a regulated casino may act shady against gamblers through unclear terms and conditions or sudden changes on it without warning gamblers beforehand. After all, what really matters is the intention of the casino's operator and not the bureaucracy the system imposes to everyone through regulations.
A thief will find a gap on any laws sooner or later to continue being a thief, while an honest man doesn't need any laws to enforce him to do the right thing.