Are the characters intrinsically bad people?
Or are they just products of their environments?
Dennis and Dee had a mom who didn't seem to give a crap about anyone other than herself. She did obviously favor Dennis over Dee, but really she didn't seem to care that much about either of them. Frank bullied them too when they were growing up.
Mac's father was a hardened criminal, and he was raised probably thinking it's normal to steal from people and treat them like crap.
Charlie's mother clearly loved her son but neglected him terribly while she was getting banged by strings of random guys. And Charlie is probably the least sociopathic of all of them.
Do you think these characters are just bad people, or did they just end up the way anyone would end up being raised the way they were?