Without proof of address, a homeless person cannot open a bank account. This person can obviously not provide proof of what he does not have.
One good way to get out of his difficult situation, is for the homeless person to find a job. However, the employer will usually require a bank account to pay his wages in. In other words, there may be no point in getting a job either, because the homeless person would not get paid anyway!
As everybody in the bitcoin world knows already, the fiat banking system is a depravity. Their treatment of the homeless is just one of the so many ways in which the fiat banks destroy the lives of the poor and the destitute.
We are at war. The ultimate goal of the bitcoin project is to eliminate the banks altogether:
A purely peer-to-peer version of electronic cash would allow online payments to be sent directly from one party to another without going through a financial institution.