Since I don't want to derail the topic too much I'll put this in spoilers so only the people that are really interested will bother. Or something.
The correct question is "Why DID the SEC want Arkansas?" Since they invited us. It isn't hypothetical, it really happened.
The answer is, Arkansas has a strong athletic tradition (especially at the time we were invited. witness: very strong decade in football along with always being a national power, very strong in baseball, among the very elite in basketball with a rich tradition, etc.), fitting the cultural and location profiles of the conference very well, and
we guaranteed we'd come if invited.
Our success has fallen off some in football, but we are on our way back to prominence after finally recovering from a series of awful coaches. In basketball, we only got better after joining the SEC, peaking at a National Championship and National runners-up in 2 successive seasons. Obviously dropped off since, but the potential is still there since we are still one of the biggest money making schools in basketball after 2 awful seasons and a less than mediocre decade. We have brought countless track and field NATIONAL championships home, and have several trips to Omaha in baseball.
Why wouldn't they have wanted us?