Southern food is great because Southern white people have a different set of culinary influences than northern white people. I don't know what that influence might be, but it must've been huge.
I don't think the point of the meme is that Mac n cheese belongs to black people. It's that GOOD Mac n cheese belongs to black people. Maybe you didn't notice, but the Mac n cheese on the left looks how it should while the one on the right looks like watery stoffers. If you didn't notice, I'd say the meme is pretty accurate.
I get that, but the Mac n cheese on the left is made by people in the south, not just black people. In fact a lot of things labeled as "black" are actually just southern. Its just the south has better food than the north. White people are eating it too.
Edit: as a European who likes spicy food, anything you're likely to get north of the Mason Dixon line is basically inedible slopp. Go eat a bowl of seafood gumbo and tell me I'm wrong. Go on, I'll wait. And while you're down there, bring me some southern maid donuts.