I do not see the really problem about this. Why should it be a problem to give personal details, if there is nothing to hide? For sure they will not share any information with others.
Most gamble sites do not publish the KYC on their site, and when you win much money they will always ask it as well. So then it is much better to state this KYC in the terms. Only good.
Only good thing is that they run this site with a valid license. We saw many unlicensed casino's the last time.
Its all about personal preferences obviously. In this case you think that it is not a big deal to do KYC but it is a big deal for some other users including me. There are still many people want to gamble anonymously especially in bitcoin/crypto gambling sites. I myself prefer not to send my personal details for my gambling activities so I will always look for gambling site with no KYC. In case of a big win, it depends on how big the win is because value is something subjective.
Of course everybody prefers not to provide personal details. You have to realize that serious gambling sites will ALWAYS ask for KYC. If they write in the TAC, that they do not, it is a lie or they will not pay you out. Unless you are a losing customer, then it is no problem. I would prefer to go through the KYC procedure with an official sites, instead of a site who operates illegal without any kind of legal license, and where I risk my money to be stolen easily.
I'm not good to any online site asking my KYC details since even if they are legit still we might put ourselves in huge risk since we still don't know if we are safe in future, But if you can afford to provide that why not? people have different perspective and those legit or shall we say almost all ask for KYC if the withdrawal a user execute a huge amount, They really need to verify if that's the case to know if the requestor is the real owner and not a hacker. I also don't want to risk my money for illegal things that's why we need to avoid the new and play with the old existing since we need to verify if those new will last and perform weell.