Certainly it's not given for everyone, but UBI would change social norms. The real question is not whether anyone would feed their pleasure side as much, more,

Certainly it's not given for everyone, but UBI would change social norms. The real question is not whether anyone would feed their pleasure side as much, more, or even "full-time" but rather that aggregate happiness and life satisfaction would grow and thus society would benefit. EDIT: If you read the end of Gruber's book, there's an exploration of this and the associated moralising.