I wonder if asking such question (and inspecting answers given) is not enough to refute the idea behind basic income - that it allows people to retrain into their desired profession, thus making the society more productive. Seeing that most people desire only a relatively small subset of careers (and almost no one want to be for example a dentist, an accountant, not to mention telemarketer or toilet cleaner), I don't…
Money becomes less valuable the more you have. For example, your first $1000 dollars buys food and shelter, while your next $1000 buys nice food and a bigger house. With BI, everyone should have the basics covered so any earned income will buy luxuries.