In "A Good Man is Hard to Find," what role does the BBQ episode play?

Similar to the
grandmother, who calls herself a lady but actually behaves pretty terribly, Red Sammy calls
himself "a good man." He does this because he sells gas on credit to boys who work at
the mill. However, he is actually quite dislikable: he is dirty and unkempt, keeps a little
monkey chained to a tree, and exhibits nasty behavior to his wife, ordering her around and
belittling her.  Listening to these two peoplethe manipulative grandmother and the man who
demeans his wife and makes her do all the worktalk about how much better things used to be is
ironic.  Neither of them is that great; so if they are the remnants of this formerly great
society they belong to, then it must not have been too wonderful.  Stopping at the restaurant
means the grandmother gets to talk to someone who shares her views, as her son, his wife, and
their kids will not tolerate such a conversation with her.  It also allows us to witness theof a
couple of jerks who insist that everyone but...