> Have you talked to homeless people?
Yes. And as a child I experienced homelessness on multiple occasions, though for all my mother's failings (alcoholism, poor choices in relationships) we never had to sleep rough. And in those types of social circles you also tend to meet all kinds of people, including people who regularly experienced homelessness (some occasionally by choice, if you call choosing alcohol or drugs over shelter a choice).
> Have you ever met a schizophrinic before?
Yes. Many times. Homeless and otherwise. And on several occasions as an adult I've endeavored to get to know them, if we crossed paths regularly. And also I've lived with adults who struggled with bipolar disorder. Indeed, one of the periods of homelessness was when my step father, lost in the bowels of severe depression, overdosed and killed himself. Not long afterward, I came home from school to the scene of the sheriff helping to toss all our belongings onto the curb.
One thing you learn growing up in circumstances that I did (and also something every decent economist would be quick to tell you) is that people say one thing but do another. (This is true of everybody, but even more so with people suffering from mental disorders.) Empathy to me means learning how to listen to people by watching what they actually do, not merely what they say. It was a skill I had to learn early on in order to make sense of my world. Learning how to "decode" adults kept me out of alot of trouble, yet also prevented me from becoming a resentful and angry person, something that happens to some people who grew up the way I did. We all struggle, some of us more than others; and specifically we struggle with competing and conflicting desires. But a just world doesn't require giving people a free pass to engage in anti-social behavior simply because they struggle and suffer. That's the sort of logic only the privileged could fashion.
No god or philosopher ever promised that figuring out how to thread the needle of treating people compassionately and humanely while maintaining a healthy social order would be easy or quick. We can't wait to "fix" social inequity or cure mental illness simply because we're too squeamish to recognize the truth of the human condition: that agency and rationality are largely fictitious, at least most of the time. Few people choose to be homeless in the normal meaning of the word. But the flip side to that coin is that exiting such circumstances (and the circumstances that led there) isn't a simple choice either. The choices that matter, good and bad, are made at moments often far removed from their consequences. For this reason, all people need to be incentivized (some more than others) to make the healthier choices. (For people who grew up in healthy homes and under secure financial conditions, these incentives are quietly inculcated as preferences.) Call it paternalism or condescension, but it's true all the same. Our society's obsession with individualism is at the root of many of our social pathologies. The very thing that induces economic inequality (individualism) is the same thing that makes us too squeamish to coerce people to obey the most basic and (for all but the most ideological) sane social norms. In both cases we simply throw our hands up because we're too wedded to the notion of individualism and "freedom".