I see that you don't address my point of commonality of interest and process at all. I would argue that, though they are fierce competitors, Alabama, Auburn, Florida, Georgia, Kentucky, LSU, Mississippi, Mississippi State, Tennessee and Vanderbilt have always had a similar approach to athletics, particularly football.
SEC football always was "the closest thing to a secular religion in the US" (George Will). Nick Saban has pointed out that the lack of professional sports in the SEC footprint prior to 1960 gave birth to and nurtured the most, passionate and dedicated fanbases in all of college sports. “So, everybody in the Southeast grew up being college fans of some kind. Whether it was football or basketball, they were college fans. And that’s why you have such passion in this league because people grew up with it, and it’s never changed. And I think that’s what makes this league a little different.”
That passion developed over decades, with no competition from pro sports. That's not the case here. There's competition from pro sports within the region and from the outside. Look at the crowds at 49er games, Kings or Warriors games, Giants games. There's always a sizable portion of the crowd wearing jerseys of the visiting teams. And those people ARE NOT all people who travelled from Pittsburg, or Dallas or wherever. While I would love to see our region 100% behind the local sports teams, it is no longer the case.
To your point, I would argue that 1) Atlanta, Baton Rouge-New Orleans, Nashville, several of the Florida markets have been, and are, comparable to Sacramento in terms of infrastructure. 2) And at least comparable, if not superior in terms of money - and especially OLD money. 3) And it isn't just HAVING the money, it's what people are willing to spend it on. The BIG money folks in the South have been willing to spend on their preferred school athletics for decades. The only schools that really have that out here are Stanford, which hasn't capitalized on it, and USC, which certainly has.