Because Wooden is that ultra-competitive :)
My as well review here since Wooden is about to open...
You've got your POWER conference (Upstate)
You've got your power conferences (Midwest, Michigan, Minnesota)
You've got your mid-majors who are almost just about as good as the power conferences (NJ, USA South, CCIW)
You've got your mid-major who's only reason they get their own line just under the mid-majors is too many sims (SoCal)
Then you've got everybody else...
All you have to do is check out the past couple NT results to see that the big 4 don't completely dominate the title scene like they used to as the world gets better and deeper. That's the DIII Wooden review.
edit: Pats, we (USA South) technically have 3 openings because Ferrum was already reserved.