Perhaps I'm underestimating the issue, but isn't there already today a sizeable chunk of the population in the world that does nothing or close to nothing, but still enjoys a good quality of life? Some people have the drive to work and create things, others are content with just consuming and making families; we have always had that, the only difference is that BI would make life easier for the latter group, but it doesn't strike to me as something that would radically change society as a whole.