That was the obvious one, but they've always had that. What has changed?
Weirdly, I think not being second fiddle to Texas and being in a conference where second-tier teams get more big-boy status. In the SWC, you're second fiddle. In the Big 12, you're second fiddle to a team that is battling to not be second fiddle with first Nebraska, then Oklahoma.
In the SEC, A&M sheds that a little. It probably can't be in the realm of current Bama, but it could push Auburn/Non-Burrow LSU if it gets things together. And third fiddle in the SEC gets you a NY6 Bowl pretty often. Cleanest path to mattering.
Plus the rest of the options
Illinois - Non-football school in non-football state surrounded by a lot of schools who care more.
North Carolina - Basketball school. Both strikes me as a place that would be OK with being OK forever, plus I just don't trust them to make back-to-back good hires.
Minnesota - Location hurts. Division hurts. Fleck seems like the kind of coach who either leaves or stays because he doesn't have the exact right place to go.
Colorado - Don't trust the geography and kind of a smoldering mess at the moment
Nebraska - Just don't like the geography, and in the midst of almost a Michigan-like run of coaching dissatisfaction. Also suffering the "ain't never gonna be what it was" curse.
Virginia - Depends how one defines mattering. I think Bronco has long-term skill. It kind of depends if the uncertainty in the middle of the ACC pulls them back into the spin cycle with Pitt and UNC and everyone else. Maybe he makes them the king of the mediocre middle, but you're basically talking engineering a Va. Tech-like rise, and I just think that's much harder to do these day.