I'd have to disagree with that. 2 or 3 bitcoinbooks have gone under in the last 3 months. After the World Cup ends, a lot more will go under. Here's a list of books that have closed or stiffed players. Some of the closed books did pay all players.
Yes, but being asked for KYC, which is what this thread is about, is no guarantee that you won't be ripped off. With how common it is nowadays, I would even say that it is a strategy to go unnoticed. Casinos are also often accused of scamming because they don't ask for KYC when you lose and they do ask for it when you have won a certain amount, although in this case, it is something that is in the ToS of legitimate casinos, even though some illegitimate ones use it as another strategy to scam you.