The obvious that you miss here is that ESPN losses nothing if FSU, Clemson, UNC etc. were to be moved to the SEC. They would all still be exclusive to ESPN.
ESPN has done nothing to stop any of this. I think that ESPN, perhaps led by Sankey and the SEC being persuasive, assumed that ESPN would keep all the most valuable ACC members by the SEC taking them. And what they have discovered is that things are not like that at all. Not even for FSU. FSU has caught the ACC bug about improved academic stature, and all kinds of people with power at FSU would take BT over SEC for that reason.
So now we have ESPN having to face such things knowing that ESON has been playing hardball against the ACC in the name of cost cutting which has led to all this mess that could mean gutting of the ACC. Just stupid all around by ESPN.
Respectfully, you have missed the point that if the ACC barn doors are open it will be a free for all. Fox would not pass on an opportunity to knock ESPN out of the northeast in collegiate sports for decades, likely a cripple blow to ESPN. Fox would likely snag Pitt and SU, both already vetted and considered prior to joining the ACC. Even if BC stayed in the ACC it would be watered down. The SEC and B1G will have taken 9-12 teams.
Don't forget, they are just beginning to realize they need cannon fodder and middle of the pack teams, especially if they plan to go to the P2 route.
ESPN is not likely to destroy one property for the other, that is the definition of tortious interference as the ACC and SEC have separate interests . ESPN cannot be caught with their pants down or everything gets exposed. The chances that ESPN are giving the SEC the nod and wink approval to move FSU and Clemson is minute, the legal implications alone are not worth the thought. Further, the losses to a profitable entity would make the entity, the ACC, worth less than it's present value, possibly less than the Big 12. Again, not a financially sound decision, which would get several big wigs within ESPN fired.
This, it is highly unlikely that ESPN does anything to destroy the ACC. They lose in the Big picture on so many fronts that it is not worth the risks.
The SEC does not rule ESPN, ESPN is the driver in that relationship. The concept that the SEC can demand ESPN to do its bidding is out of whack, the concept would prove extortion on some levels. ESPN makes lots of money off the SEC and will listen to the SEC but ESPN is not likely to destroy the ACC to benefit the SEC nor to give up territory to the B1G.