There is a large difference between doing nothing, and doing nothing of value to society.
For example, I love to learn. I could spend ages reading books and learning as much as possible for my meager brain to understand about physics and it would be very fulfilling.
But unless I apply that knowledge, it really wasn't of much value to anyone (even myself, depending on how you look at it).
So why do I deserve to take advantage of all society would provide with basic income (food, shelter, safety, etc..) if I provided nothing in return?
Ok, I see, but after you spend 5 years of your life learning you will be able to do a lot of thing.
Now, why should you start doing something different from learning ?
Maybe because if you do something productive you will product value that will let you to live in a better house, or to learn more...
The point is not to let everybody doing nothing of productive, the point is to give to everybody the choice, between doing nothing of productive now vs. bringing values to the society...
I have been surprised over and over again at the powerful force that is doing "just enough" to get by. So many people are affected by it. It's really quite impressive.
You know those bars you go to? Restaurants? Theatres? The list goes on. No one would work at those shitty jobs any more. Because 25k is comfortable - why would I work at a shitty job for another few thousand?
However, in my opinion, the point is that nobody should work at such "shitty jobs", who enjoy being a waiter, will be one in some high end restaurant where he will compensate in an extremely honest way.
The introduction of basic income will need a complete mental switch.
We can dream about robot that serve us, or we can start to realize that the quicker way would be to change mentality and stop to need somebody (or something) that serve us.
I think the challenge is we are currently in the middle of a transitionary period towards full automation of "shitty jobs." Basic income is a logical model once those shitty jobs have been commoditized: there is no need for the jobs, and the people who normally would only be qualified for those jobs need to survive somehow.
But we're not there yet, our economy is still reliant upon a large number of people doing "shitty jobs" in order to grow in general, and more specifically to continue this push towards further automation. This is the challenge: you need a way to alleviate human suffering during the transition towards a greater world for everyone, but the most obvious way to do that (basic income) may halt the transition itself. What we probably need is something that looks more like a bridge than a final destination, but any such bridge starts to resemble the experiments in communism that cost the world so much during the 20th century.