UBI essentially assumes that everyone is a rational actor and that they will not succumb to spending the basic income on non-productive things (drugs, alcohol, gambling, excessively expensive consumables, etc). This is demonstrably false, especially if individuals don't have a day job. On an individual level it's easy to say that people should be responsible for their own wellbeing. But as a matter of public policy, it's just plain bad policy.
It's also hard to see how that money would /not/ be extracted in the form of higher prices across the board.
And the main point of the article is a very good one: what happens to all the now-unskilled labour?