Is this something new? Because I have never heard that mentioned sites asked anyone for KYC, although it is or might be written in their TOS. 
To be honest all fiat casinos are enforcing KYC and with all this regulations and buzz around crypto I think we might see KYC in every crypto site, not only casinos. It is just matter of time.

As I can see you didn't do any kind of research and I wonder what is real purpose of this thread, because if you did research you would have known that 999dice is scam.
But yeah, go with "they don't ask for KYC and they are just fine"