Atticus says that the Ewells are people of disrepute, who have been so for generations, which implies that their lifestyle has become a custom. He further avers that they cannot be changed or displaced, for they would not fit in a normal, decent society - they are uncivilized and would never adjust. They reject education and only use it as a means to an end - since they live in abject poverty, they receive a social grant from the state, as long as the children are registered for school.
Atticus is furthermore of the opinion that they live like animals. The Ewells live in absolute squalor and filth. They are looked down upon by the rest of the inhabitants of Maycomb. Everyone ignores them and no one does anything about their criminal activities. In this sense then, they are privileged. Since they are white, it seems, their crimes are ignored - an indication of the injustice of racial profiling and disparity at the time.
Atticus is a decent and well-respected citizen and he wishes to instill in Scout the morals and values that would make her a respected member of society. It is therefore obvious that he wishes her to 'see the other side' as it were, so that she can make appropriate value judgements.
I find it interesting how, although he clearly wants to combat racism in maycolm, Atticus seems completely oblivious to discrimination against the lower classes. He doesn't seem to care much about the fact that Mayella is beaten and raped by her father. None of the characters, who are presented as "good folk" (like Atticus and Judge Taylor) seem to think twice about Mayella Ewell and the children who are abused by their father, and then when he dies, there is no mention of what is going to happen to them all.