For some, hard work is what gives them satisfaction in life. If robots and computers take over everything, many aren't going to be able to adjust, they won't feel they're making a contribution, getting their hands dirty. Seen many who lose their jobs or retire sink into depression, don't know what to do with themselves. Not all have hobbies they can fall back on, and something tells me UBI won't allow anyone to live comfortably/prosperous.