If the Curacao license is the easiest one to get, that's why all casinos get it. On the other hand, any license, even Curacao, imposes some restrictions on the operation of the casino and the casino must comply with all the requirements of the regulator, otherwise it will lose its license and will not be able to operate legally.
You need to get used to the fact that cryptocurrency will soon be fully regulated and licenses will be needed for everything, both for exchanges and for casinos.