The US has a very strong thread of Calvinist/Puritan/Protestant theology and thought running through its cultural foundations. One of the effects of this is a cultural predisposition to believe in something approximating the Just World theory—that is, that if someone is rich, it is because they are a better person (or blessed by God, or destined to be rich), while if they are poor it is because they are inferior people who deserve to be so.
This cultural background makes it very easy for people to look at their own lives and see their successes as their own work, and their failures as bad luck—but then look at other people's lives and see both success and failure as being 100% a product of their own deserving. (When in reality, everyone's successes and failures are a blend of luck and merit, with a pretty heavy emphasis on the luck, especially the luck of what family you were born into.)
I believe that some form of this is pretty common in general simply because that's how people cope with the very fact that homelessness exists in the first place. Like, it's either a massive injustice that pretty much demands that you, personally do something significant about it... or it's "just the way it is", and you can look away. But this latter outlook requires some amount of dehumanization, so people rationalize that the best they can.
This is correct. It goes deeper than this, too. Capitalist economies rely on a myth of meritocracy for labor.
The end result is that we’re forced to view the homeless as lesser. We typically throw around words like addict, because we have to. If we admit that there’s homeless people out there who got so based purely on bad luck, that destroys the promise of America.
This cultural background makes it very easy for people to look at their own lives and see their successes as their own work, and their failures as bad luck—but then look at other people's lives and see both success and failure as being 100% a product of their own deserving. (When in reality, everyone's successes and failures are a blend of luck and merit, with a pretty heavy emphasis on the luck, especially the luck of what family you were born into.)