Mandatory KYC is imposed by the government which can't be in the hands of gambling sites but sometimes site is also using this KYC as a weapon to stop paying the huge rewards in case if the Gambler violated terms or can't able to verify the real identity for some reasons.
And that made Gambling site powerless against obligatory because even if they wanna sustain the promises to their players but their hands are tight from the Government policies .
i may not blame casinos then even how irritating changes from the recent rules but of course if you don't want KYC then play in real casino and not in Online sites.