The problem is (a) people feel bad about being on welfare, and (b) we stop paying welfare again the moment that worker makes any money, creating a disincentive to engage in any form of small scale productive activity.
Some of the pro-basic income folks (and myself) believe that a basic income helps with both of these points. There isn't much stigma to getting welfare that everyone gets, though possibly the extra that those that need it get.
And since it doesn't stop, there isn't that sort of disincentive towards going to work as work simply enhances it - folks might actually be more inclined to work, albeit fewer total hours.
Even with current welfare systems, there are ways to minimize these things. Creating a tapering system so that folks are Always better off working, more trust in the welfare system itself, and not treating recipients like criminals or second-class citizens.
I. am. a. person. I want... proooductive. I want... puurpose. I will. Take the orders. From a capital-supplier. To proooduce economic vallll-ue.
I. am. Totally. Not. a robot.
beep beep
/s
Seriously, though? People want to be exploited because they need a wage-paying employer to give them purpose? Then where are all the people who don't work for someone else getting this much-vaunted "purpose", eh? Whatever happened to all that individualism stuff, about people being ends rather than means?
People can be both ends and means and be quite content. Personally, I think there is too much emphasis on people being ends unto themselves in the current culture. Madonna is a great example of this. She ceased to be entertaining more than 30 years ago, yet I still come across news snippets about her. Why?
That's because society is really nothing but a lot of people working together in an alliance. If we didn't make people themselves the end they would have no reason to participate in society.