Lots of libertarians like UBI; it's pretty much the smallest government you can have that still ensures a floor to everyone's quality of life. Milton Friedman advocated a negative income tax, which is similar.
I must have been unclear; the question is should we allow people to leverage their UBI, and should we guarantee people food and medical care if they are careless with their UBI.
Libertarians would probably say "maybe" and "no" respectively, while others are more likely to say "no" and "yes".
Personal responsibility and freedom imply the freedom to be irresponsible and starve. Lots of people feel icky about that.
