Some people ask why, because it doesn't make sense.
Well, if the Pac 12 gets Oklahoma, Texas, and Oklahoma State, that right there gives them three top 25 teams right now, AND two top 10 programs historically.
Sure the SEC is adding TAMU. And let's say they add Mizzou and Va. Tech (for argument's sake).
Those are decent programs. Only one of them has a singular national title. TAMU and Mizzou haven't won a conference title in forever. Va. Tech is a good program, but would be a 7-5/8-4 program in the SEC.
Florida State adds another power. Jumbo Fisher has that program on the right track. Since about the early 80's, Florida State has been a collegiate power. Fisher has a top five team right now. So you add prestige. It makes some sense monetary wise, even though you could West Virginia and add a bigger market. But not football wise. WVU would be another 6-6/7-5 program.
Adding Florida State would add a powerhouse and make the SEC way more competitive. Which means more powerhouses=Better conferences=More Money.