This is not some grand conspiracy. The Big 12/ACC will continue to get slighted while the "best" G5 team(s) get over-ranked to give the B1G/SEC 1) the maximum available slots and 2) the easiest path to the quarters/semis.
Don't believe me? Look no further than the "top 20" matchup between BSU and UNLV. It's a win-win for the blue bloods. BSU wins, they get the 3 or the 4 seed at the expense of one of the Big 12/ACC teams. UNLV wins, BSU will only drop down a few spots to nearly guarantee a second Big 12/ACC team doesn't get in. Only scenario I can see where that doesn't happen is if SMU loses. They're probably still in and Alabama drops out, but it will be close.