In my opinion, before you raise such a question, you must first have reliable information, why cryptocurrency users are afraid to provide passport data and why the gambling site should be provided to KYC. Although if you return back in 2016, the popularity of cryptocurrency spread not only because of its volatility, but also because of the possibility of anonymously owning your assets. Today, anonymity melts like ice.
The question sounds very dumb to me. Those who hate submitting the KYC form definitely have their reasons for doing that, and like you said, anonymity was truly what everyone appreciated most about cryptocurrency system. I remember vividly that it was the exact reason I got convinced to go into casino gambling.
But, what I see today is totally an opposite of it was then. Why even ask for these details at all? The questions asked, are they not intruding into a players private affair? And also, how do we trust these sites wholeheartedly to be sure the information is safe with them. All this are the reasons why most gambles never find filling KYC form interesting at.