I would suggest it was the requirement to work? I vaguely remember reading in The Forgotten Man by Amity Shlaes that for all of their confusion the Roosevelt administration knew that just giving away money would be bad for people. It would destroy their pride and sense of self worth. I don’t have the book available right now so I can’t find the quotes but I am pretty sure she took that position.
Welfare as we know it started for the best of reasons but the Progressives behind it have a flawed view of the nature of human beings. They assumed that society was the problem and if you could hand out enough money, people would respond by taking what they need and going back to work. The traditional view of human nature, found in the Bible, is that mankind is wired so that most people will take whatever you give them and still not want to get up to go to work.
We can get people off the dole but it will be painful. In the words of Solomon,
(Proverbs 16:26 NAS77) A worker's appetite works for him, For his hunger urges him on.I am not sure we are willing to pay the price.
Shlaes, Amity. The Forgotten Man. New York: Harper Perennial, 2007.
homo unius libri