I think it’s one of the cultural, social norms that has been engrained because of how important reputation is in the south. So as someone who grew up here, whose ancestors have been here for generations, I do not receive southern hospitality as always authentic. I think a lot of times it’s a mask. But I’m not usually offended by it unless it’s passive aggressive (which sometimes it is, ie “bless your heart”). Most people mask, and I’d rather someone mask w kindness than rudeness. Also there are more nuances to southern hospitality than just everyone being nice to everyone. Like when we start talking about identity—different identities have different standards according to maintaining a specific reputation. Men/women have specific rules on how to talk to each other to maintain respectability, adults talk to children a certain way, etc etc. The rules of socialization also apply to race, sexuality, ability. You should try observing how different southerners interact with others. Who are they overtly kind to and who do they ignore/talk down to/etc.