[Grishnakh]

Exactly. And what's more, they are productive, even if they just subsist on UBI alone. They're getting their UBI mostly from extremely wealthy people, who would otherwise hoard it mostly. By redistributing it to poor people, it's going to be spread around in the economy more, creating economic gains. These people are going to spend it on rent, food, clothes, maybe a car, and various other stuff. They might not be creating any wealth, but they're advancing the economy, which will create wealth elsewhere (such as when someone comes up with a new business to provide a useful service to these UBI "leaches"). And more tax revenue will be generated from their economic activity too. This is why wealth concentration at the top is so bad: the wealth stagnates and does nothing for the economy when it's just held in offshore bank accounts; when it's spent, even on booze, it has many consequential effects: paying for bartenders, janitors at the pub, delivery drivers (maybe not with robo-trucks...), brewery employees, etc.

Finally, you never know what these "lazy" people will spawn: one of their kids could become a great author or scientist or something.