...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.
Yeah that what he is referring to, that because of addiction, someone might find it really hard to be well disciplined on managing our money.
Greed and addiction correlates with each other, and they can make you to lose money and eventually yourself.
So we must keep plans healthy when we are gambling and we must avoid being addicted where we cannot control ourselves anymore.