But should we also be supporting people who are certainly capable of working, yet choose not to?
I think that is the goal we should be striving for. I like the John Adams line: "I must study Politicks and War that my sons may have liberty to study Mathematicks and Philosophy. My sons ought to study Mathematicks and Philosophy, Geography, natural History, Naval Architecture, navigation, Commerce, and Agriculture, in order to give their Children a right to study Painting, Poetry, Musick, Architecture, Statuary, Tapestry, and Porcelaine."
Or more simply, "I am a soldier so my son can be a shop-keeper and so his son can be an artist."
I think it will be a long time before we get close to the kind of post-scarcity economy that would allow this kind of lifestyle though - if ever. Maybe it can only exist in the realm of science fiction. But I think it is a noble goal to strive for.
In the meantime though: I agree with you. I think if we're going to have a UBI or whatever social program it should be based on subsistence and survival for now, with a view to getting people to want to join the economy if they want more.