...Addiction is the biggest enemy here...
No, it is not addiction, it is ourselves. Humans are natural sinners and greed is just a part of us. The biggest enemy here is ourselves, how we will be able to stop those losses, how to stop betting when we don't need to bet anymore, to decide correctly. If we will be able to control ourselves we don't need this cap to stop us from gambling, we can do that ourselves.
With simple awareness, you can know if you are in right mindset where if you are thinking right and good. Greed is part of human nature but we can control it if we have discipline. Actually self discipline is one of the hardest human achievement because it requires commitment after all. A gambler should know when to start and when to stop or to backout. Discipline can also include the money that you are only wanting to risk and spend in order to avoid to lose more money.