There are plenty of people who do work but still can't cover their basic needs reliably (minimum wage isn't nearly enough in big cities but cities still need the jobs that pay minimum wage) and then people who can't work (infirmity or lack of skills).
Why should money just accumulate at the top where it's marginal utility is vastly smaller than if it were in the hands of the bottom portion of our population?
Finally why should work be the measure of a person's worth to the point of denying basic survival if you don't?
Of course there will always be people who cannot work. But the point is, BI is a basic income for anyone. No strings attached, Here's OPM, even for people who could make a living without BI. Strikes me as a waste of taxpayer's money?
Providing a wide ranging universal safety net seems like exactly the kind of thing that government is best suited for over any other institution. There's a lot of places it could wind up saving money over the current system anyways: practically no administration costs, lower health costs because people aren't forced to live in shitty places that make them sick because they're too poor to move somewhere else.
Even if it winds up costing more I don't classify giving everyone the freedom to live their life in a way of their choosing ultimately as a waste. Hell that's the basic utopian dream from Star Trek, Culture or a thousand other places, so much wealth that anyone can do anything with their lives and it's a rounding error. Are we there, no, but we have the surplus to take care of everyone's basic needs today.
Government fails in most areas. I agree with your point about administration costs, but don't you think politicians will come up with other things that they can spend the saved money on?
There's a lot of things they could spend money on that also wouldn't be a waste of money. Infrastructure could really use more money, the space program could definitely benefit from a pile of cash to both the public and private sectors, and funding for education is in serious need of an increase (as well as reforms to improve effectiveness).
Just because the government wastes money some places doesn't mean they're incapable of putting it to good use in other ways or that we should avoid good programs just because they might misspend savings from it.
Why should money just accumulate at the top where it's marginal utility is vastly smaller than if it were in the hands of the bottom portion of our population?
Finally why should work be the measure of a person's worth to the point of denying basic survival if you don't?