Not to be insensitive, but any social worker could have told you all this. It's a pretty well established fact that the single biggest challenge in getting the long-term homeless back on their feet is not resources, it's repairing the damage done to their psyche.
For a greatly simplified explanation, consider that studies show positive emotions have a huge impact on psychological resilience, and homeless people do not have significant amounts of positive emotional reinforcement - though they do have plenty of adverse and stressful life experiences. Children who grow up in negative, impoverished, or homeless situations are found to become developmentally stunted, though some of the effects can be reversed in quality foster care.
For a greatly simplified explanation, consider that studies show positive emotions have a huge impact on psychological resilience, and homeless people do not have significant amounts of positive emotional reinforcement - though they do have plenty of adverse and stressful life experiences. Children who grow up in negative, impoverished, or homeless situations are found to become developmentally stunted, though some of the effects can be reversed in quality foster care.