I think we also have to realize that not everyone who is homeless has problems that can explain it away.
It's easy to look at someone who is homeless and tell yourself, "Oh, he's a dope addict. He did this to himself." It's only very rarely true, and you're only making excuses for not helping another human being.
Just last year there were newspaper articles about how a shocking number of perfectly normal public school teachers in California live out of their cars, just because they cannot afford a place to live on what they're paid.
Most people, especially in the SV bubble, would be shocked to learn how many of the baristas, maids, security guards, convenience store clerks, and other people they encounter every single day are homeless, living in their cars, or sleeping on other people's couches through no fault of their own.