I agree, it is dumb for a casino not to KYC a player before they sign up, because they could deposit their own money/receive a tip, and try to withdraw but that money is just gone. Makes me think some casinos are thieves, such as roobet. Happened to me, but I ended up just KYCing, but for people who don’t have it available, they just have frozen money.
It is just a strategy. Casino wants to get new gamblers and their money, but someone don`t like KYC, someone more don`t want to wait KYC, etc. And the moment of cheating - if the gambler win, casino can KYC him for a long time and as result can say that he has some mistakes in his data. I don`t want to name any casino, but i know several with such strategy.