I think a lot of it is the disconnect that happens when you've been well taken care of all your life. If you had to work in school, and then apply for jobs, and then had to show up and do the work, but it was all pretty much straightforward and fair, then it's easy to think that if someone doesn't have enough money to live they probably just aren't doing those easy life things and it's their fault and nothing needs to change.
If you've had experience on the unfair side, it looks totally different.