"friendly people" but also "hateful racist trumpers"? Well which is it?
Another native Carolinian chiming in here (from NC, but similar).
These people are friendly if you "pass" as one of them. Be white, wear a trucker cap, don't dress up too fancy, use a southern accent (or at least, don't talk too pretty), don't be gay, don't say a damn thing about politics or religion. Don't drive a Prius or something. You're good to go. If you are careful enough they might even occasionally start confiding in you, and expect you to agree with them, about their casually racist views. If you reach this point, you can get by with just not saying anything, and the conversation will usually evolve to other less difficult matters.
You can violate these rules, of course, but you need to be able to "pass" by compensating in other ways. So if you do wear a suit and drive a Tesla, you could make up for it if you have a good southern accent or go to church or proudly espouse your conservative values in some other way (carry a sidearm, maybe).
Also, my people will sometimes act nice to you even if they hate you. If you're here a while you will learn to recognize it. Southern "hospitality" is incredibly superficial - there's a thin veneer. If you don't look too closely, and you don't care too much about what they really think of you (because really, they're mostly harmless - unless you need something from them), you will be OK.
... unless you have kids. Please don't send kids to public schools in the rural white south if you or they are even vaguely progressive.
From my point of view you just described the left.
Dressing in a suit and tie is not a rarity in the south or rural areas. Being gay isn't some attribute that qualifies for special treatment just because of your sexual preference. Politics also isn't some defining feature, and is WAY too publicized in today's culture. Why does it matter what someone's political view points are? Does that make them less than you, and are they really racist or is it because you don't agree? Because conservatives think democrats are racist for implying POCs aren't capable of doing things themselves. Maybe southern hospitality is superficial in some southerners but at least its some kind of hospitality, have you been to any major city? They'll let you bleed out before calling for help.
I really do want to emphasize how polite rural people can be to your face while shit talking you behind your back, though. The idyllic and friendly "country folk" lifestyle is really bullshit. I grew up in such a community and we would smile and "yes sir" all day long to people's faces then talk total trash about them the second they walk away.
If you don't look too close and you don't care to make friends with them, you won't notice. Some fancy city liberal who moves in and minds their own business is unlikely to have any direct conflict, while still eliciting a massive amount of gossip and vitriol "under the hood."
An introverted HN programmer, working from home and staying out of the way, may only ever notice the good. But if you really want to be "part of" a community like this - as in, having real friends there - you will see a different side of things.
"Bless your heart"
That's what they mean, I'd assume.