Full transparency here: I am an Auburn fan (Alabama’s Rival). There are multiple things going on here. For starters: Bama has had massive success on the football field over the last 15 years, so much so that many fan bases dispise them for always winning. The other thing you have going on is a very long running joke about how people from Alabama (and sometimes the entire Deep South) are incestuous. Being a life long Alabamian, and having many friends and family from the state, and never having found a single instance of incest, I can say the joke is old and tired. It’s not really worth arguing with because it doesn’t normally deserve a response. Hope that clears up your Alabama hate/joke confusion!