It's an interesting thought experiment but it fails to consider healthcare. Infinite healthcare for extremely unhealthy drug addicts would be impossible to finance.
Isn't that the point of this, to gather them together and let them die in a drug addled slavery. Wasn't this the big surprise end of spoilers A Scanner Darkly or reminicent of "The Planet of Sin" in one of Heinlein's stories? All they guy needs is some South American mind control drug and he can then change his name to "Jim Jones".
That's not what he says at all. They are on UBI and don't add anything to society. He states it explicitly.