It's just an option. Of course Auburn and Tennessee would be attractive, but getting a program to the top of the SEC will be significantly harder than it will be to get BC to the top of the ACC. You also have to factor in the quality of kids you can recruit, which would be substantially better in the SEC, but everyone is grabbing them. It's a toss-up and he very well could go to Tennessee or Auburn if they open up, but I don't think it's confounding as to why he would go to BC.
Auburn was not only at the top of the SEC 2 years ago, they were at the top of all of college football. Even if everything were going perfect at BC, they'd be what, the 4th, 5th, 6th most talked about team in their conference? And Miami may very well have big problems on the horizon, but even so, it's still probably easier to get kids to go to Miami for football despite that than BC. You're right that different cultures may exist and the quality of kids you get at Miami and BC, but it's a step-back of a job...already within his current conference. It'd be like Les Miles leaving LSU to go to Vanderbilt. Auburn and Tennessee are committed to having a PREMIER football team (money, facilities, support, and even under the table stuff). BC...well, they're committed to simply having a football team.
Just don't see him leaving Miami...to take over BC...especially if Tennessee and Auburn are options as well.
I'll eat Wooly's shoe if this happens.