Exchanges and casinos block ips from the United States but everyone just uses a VPN, why even block their ips in the first place when you know they are going to do it anyways. I'm guessing they do it so they have some type of deniability?
A lot of illegal things are prohibited but people do it anyway, why to block them? And finally we all die, so why to work and live? Not a logical question man.
There are a lot of people who are afraid and don't try to gamble with VPN and by using other services, also there are a lot of people who don't know what's VPN and how to use it. In any way, prohibiting of something reduces number of users because of afraid, not much knowledge and other reasons.