Would they, though? That's the key question that I believe this study (and others like it) fail to address. Depending on the basic income amount, I believe it would be possible to live a fulfilling (if somewhat minimalist) life without needing to supplement that income.
With BI I could spend more, but I would still keep on working towards a relaxing financial freedom where money is not a problem at all.
Yes, this requires employer flexibility and the move from 40h->15h per week grants much less freedom than stopping work entirely but masses of people suddenly being content with a minimum amount of money does not sound convincing to me at all.
Living off the basics is pretty dull. Most people who live ascetic lifestyles by choice usually come from a position of relative wealth and choose it more as an aesthetic or affectation than anything.
All in all, I think there are enough people that things would be fine.
Anecdotally my friend is part Native-American and gets 4k/mo from the tribe's casino money and they're bumping it up more soon. She's chosen to be a stay at home mom.
A better question would be, "how many would report their work out of an entire country was offered a basic income?" There are already data points for comparison, when that question is asked.
An interesting question is "can we reasonably automate things that people currently get paid less for than a basic income would be, or will we have to pay them more, and if we have to pay them more, what will be the economic effect of that?"
People on HN are significantly different and not even close to a representative sample. No one at any point is saying that HN readers are better or more moral, but there are huge, huge differences in technical skill, intelligence, knowledge, college attendance rates, social skills, empathy, and so forth compared to an average sampling of the population of the United States. I'll leave it up to everyone to decide which direction the arrow points in the above fields.
You are making arguments against things I never wrote, which is a strawman fallacy.