It is not that the homeless population does not want to save money either; it's that they cannot. Without a residential address, it is extraordinarily difficult to open a bank account, and banks may charge fees that homeless people may not be able to afford
Panhandling is not a steady income. It is not that homeless people are disincentivized to save, it is that from daily costs of living, they do not make enough income to even collect savings. Furthermore, savings may be stolen or lost when living in a hazardous environment. A homeless person's environment may not allow them the luxury of saving money, even if they wanted to.