I guess when you are rich you forget the times when you are poor, or if you are born rich and never experienced what is it like to be poor, then that's the attitude towards the poor. Hope that all those that are rich experience a day or two of being real down and under. Perhaps they can then understand how is it like. Especially for politicians, they are the ones that need such experiences.
Homeless is a very loose term. Most of the people you described I would call are destitute and the few coins that you would spend on a mars bar would help them out.