Casinos know that if they asked for this information upfront a great deal of players will not bother... I think casinos keep this information hidden so scammers do not abuse their policies
I agree with the first part and I totally understand why most casinos do not enforce kyc on registration as this will result in them losing many of potential customers. But the reason you mentioned isn't reasonable and some may even consider it unethical since a good service provider has to as clear and transparent as possible with its customers when it comes to their policies.
The fact that KYC means disclosing some of our important information then maybe some gamblers tend to refuse to do KYC. But this is the trend now, even the most reputable gambling casinos have already required KYC, so it’s up to us if we will still gamble on their sites or not. However, the OP might have misunderstood Duelbits rules and policies and so he is not in favor in it. But for most of the gamblers here, even myself, I find Duelbits just fine to gamble.
Obviously Duelbits is a great casino to play at, but which casino does not require KYC and is trustworthy? which one? If along the way you may run into a casino that says that they do not have or require the KYC, but that they can ask for the KYC when it is to withdraw, and it may happen that when they comply with the KYC they do not approve it and do not give the money.
In Duelbits things are more transparent, the KYC is soft, it is not as aggressive as in other sites, if a person has problems with the KYC it is because they must send it properly, be as sincere as possible, if there is this type of care, no there must be some problem.
When a casino determines that there are problems in the KYC it is because there is something strange and that is what they let you know.