If I get you rightly, you are saying the self-exclusion option should not be made directly through casinos, but through a separate agency that will enforce the restriction across all casinos within its jurisdiction. Yes, I like that option. Some casinos are not making any deliberate effort to self-exclude their customers who are obviously gambling beyond their limits. Those customers bring them more money, so they will choose to go against the gambling rule than let the customer go.
Addiction is not a joke. Addicted gamblers need to follow strict measures to achieve their aim of recovery. An agency that is capable of restricting them from using all gambling platforms within its jurisdiction will do gamblers a lot of good. This time, there will no longer be cheating or secret gambling. Once you're done, you're done for good until your self-exclusion period is completed.
You are right, it will be very essential and beneficial to one's life, if they are being forced to leave any casino bet for good, they might see it as wickedness but when they will later realize the good you done for them, they will come back later thanking good, if not this way, it will be difficult to help someone who is really addicted to the game, as it will prevent and protect them from a lot of problems that would have ruined their lives.
If I am losing money, and a casino tells me that they are cutting me off, I would actually thank that place. Because after all, a casino exists for one reason which is making a profit, and they could have just let me ruin my life and they would get richer, and yet they are not and they are stopping me which means they are a great business.
Do you see McDonald's rejecting to serve fat people? Do you see any cigarette companies rejecting to sell it to cancer patients? Do you see any business really, stop selling their items to their customers for any reason? They would be glad to take your money, so if a casino can get richer if they keep me playing and yet they still think of me and make me stop then they are a great business.