One Last Football Pass

Apparently there are some football games this weekend:

#5 Virginia Tech (10-1, 7-1 ACC) plays Florida State (7-4, 5-3 ACC). #10 Miami (9-2, 6-2 ACC) is not playing.

#2 Texas (11-0, 8-0 Big 12) goes up against Colorado (7-4, 5-3 Big 12). #16 Texas Tech (9-2, 6-2 Big 12) seems to not have a game.

#3 LSU (10-1, 7-1 SEC) meets #13 Georgia (9-2, 6-2 SEC) in an actual exciting matchup. #9 Auburn (9-2, 7-1 SEC) could use a scrimmage or something this weekend, though. (This is only fourth time in the last ten years the West Division has produced a team with less than two conference losses, by the way.)

So my question is this - why is the championship not just between the top two conference teams?

The only purpose of these championship games are the huge sackfuls of cash to avoid Big Ten scenarios where the champion doesn't have to go through the best conference teams. But two teams in opposite divisions are still going to have six opponents in common (unless the play one another, in which case we have a definite metric as to which is better). A 7-1 second place team in one division is going to be better than a 6-2 champion in the other no matter how the divisions are stacked. Why are Miami and Texas Tech sitting on the couch this weekend?