It's called a basic income because it's subsistence living. Most people won't just live off it and do nothing. And those that would, well, they aren't really going to do much anyway if you force them to work, other than the bare minimum of the most menial labor.
So far every experiment in UBI has shown that almost everyone getting it does something useful with the money and doesn't just sit on it.
And frankly, I have no problem with paying someone to sit on their ass drawing lines, if it means they aren't starving and homeless.
He clearly doesn't expect everyone to be generous, hence why he advocates for UBI. UBI would be mandated and would therefore force participation from those without such generosity (according to their means, of course). By claiming that he holds a viewpoint which he obviously does not you've utterly failed to refute his argument. Perhaps you should seriously consider why his argument works and yours doesn't. You may come to a surprising change in your point of view.
So far every experiment in UBI has shown that almost everyone getting it does something useful with the money and doesn't just sit on it.
And frankly, I have no problem with paying someone to sit on their ass drawing lines, if it means they aren't starving and homeless.