Dude lol. D&D Shorts agrees with you?
Who next, a luminary such as Howard Stern?
Like D&D Shorts is great if you want weird D&D gossip, especially a couple of years ago. But his takes on D&D subjects tend to be well, very much hotter than the surface of Athas, that's for sure, and often just absolutely provably wrong, because he is like, relatively young but sometimes talking about stuff from before his time and more than a little bit prone to just going off in flights of fancy.
They already changed that in 4E Dark Sun, no chance they go back to the 2E take.
Look man, if you think the "main theme" of Dark Sun is "If you don't have gods, the world is hell and you are evil!", then yeah, I could see believing that another "major" theme of Dark Sun was people-breeding, but again, I don't think you're helping your position of "I KNOW WHAT DARK SUN IS ABOUT!!!" by saying that lol. I'm sorry this is genuinely making me laugh a lot IRL, no hate, you do you! If it's what you like, it's what you like!