I agree that there are people who will not transcend to become ultra productive members of society. However, I see everything you said as an argument in favor of UBI, not against. No one would have to fake disabilities, throw money away at a BMW, or have kids they don't want. Also many times the impact of a stable source of income isn't realized until much later when people realize that they are free to do other things than worry about money all day. I don't see what's wrong with making people less miserable, I don't care if they spend the money on alcohol or whatever thing society deems immoral. Life is hard and it's getting harder, this is just a cushion.