What is a good man to the grandmother and to the narator?it still not clear to me what is a good man according to the story

As soon as this short story begins, the grandmother is
reminiscing about how things used to be - "back in my day" when children had respect for
their elders and when men were "gentlemen." She talks about the man she almost married,
a Mr. Teagarden, who brought her watermelons. He was a gentlemen. When the family
arrives at Red Sammy's Barbecue, the grandmother shares memories with Red Sammy about
how people used to be able to be trusted but that nowadays, "People are certainly not
nice like they used to be." Red Sammy shares a story of how he let some men charge
gasoline at his station, and the grandmother assures him it is because "You're a good
man!" When they talk about the Misfit being loose in the country, Red Sammy
says:

A good
man is hard to find. Everything is getting terrible. I remember the day you could go off
and leave your screen door unlatched. Not no
more.

The grandmother prides
herself on being able to recognize a good man. Ironically, this gets her and her family
killed because she recognizes the Misfit when he and his gang stop on the road after the
grandmother and her family have an accident. The Misfit tells her that it is too bad she
recognized him:

readability="7">

It would have been better for all of you, lady,
if you hadn't of reckernized
me

From this point on, the
grandmother panics and keeps trying to assure the Misfit that he is a good man, that he
comes from good people, that she is certain he is a good man, that he would not shoot an
old lady, etc. This is ironic because the Misfit is NOT a good man, and the
grandmother's definition of a "good man" has been hollow and meaningless, just like the
platitudes she is always saying - "A good man is hard to find," or "Things were better
in my day." Many, many of O'Connor's short stories contain these empty platitudes and
they show the hypocrisy and emptiness of the people that utter
them.

So -- what is a good man? No one knows. This is an
empty statement. The grandmother thinks she knows what a good man is, but she does not.
She has been so caught up in her selfish desire to visit her childhood home that she has
put the family in danger. She has selfishly taken her cat on the trip, which winds up
causing the accident. She is a petty woman who utters empty phrases such as "a good man
is hard to find."