Divisional play certainly has its positives and negatives. It adds excitement to the mix as more teams are in play going into November than the past. However, there are weird quirks that just don't sit right, such as the one you mention.
The other quirk that doesn't sit right with me is how a divisional champion is decided. One part of me gets why it is based upon how you perform in all of your conference games, but there is another part that thinks a divisional champion should be based only on divisional play.
I look at one possible scenario this year where Ohio State could go 5-0 in their division, yet not win it if Penn State doesn't lose another game besides Ohio State and goes 4-1 in the division. Again, part of me gets it as they would have a better conference record; but the other part of me asks if Ohio State is undefeated in the division and beats Penn State, why should their two losses against non-divisional opponents affect the division's outcome? It gets even worse when one looks at the cross-divisional opponents of the two schools: Ohio State has Nebraska (7-1), Michigan State (6-2), and Michigan (7-1); while Penn State has Nebraska (7-1), Iowa (5-3), and Northwestern (3-5). Something just doesn't sit right with such a scenario.
I am going to point out all the reasons why I think changing this rule would be a bad idea.
First off, if this were the rule, then why even play inter-division games? If you don't count them, then they just become the same as a non-conference game.
Also, if we just had to go 5-0, then the Michigan game at the end of this year would have far less on the line. One of the things that has made that game great is that there is usually conference championships on the line. Granted I'd care more about this game than any other, even if nothing but beating their asses was on the line.
Additionally, no sport just uses division games. And I'm pretty sure none of the other conferences do either. If we did, it would only be a matter of time before the B1G championship game would become a big joke for the nation. Imagine a scenario for next year...
Ohio State is 11-1 (7-1), with their only loss to Penn State on the road, but have wins against Michigan, Nebraska, and at Michigan State, plus the other four Leaders division teams.
Penn State has an up and down year, going 8-4 (5-3), with a non conference loss at Virginia, and losses at Iowa, at Nebraska, and against Northwestern, but beat the five Leaders division teams.
Nebraska is 11-1 (7-1), with their only loss coming to Ohio State.
Under current rules, the championship game is Ohio State vs. Nebraska. But if the rules were changed, it would be Penn State vs. Nebraska. I am sure most Buckeyes would be furious. The nation would laugh at the stupidity of the conference, and what could be even worse, is maybe Nebraska gets the win, and gets the nod to the NCG over Ohio State, or two non B1G teams get it. Whereas, if Ohio State played Nebraska, then the winner would get the SOS boost to get into the NCG.
Bottom line is this...if you somehow do go 5-0 in the division, then the ONLY way you can get kept out of the CCG is if you go 1-2 in games vs. the other division, and this assumes another team in your division goes 7-1. That seems fair. This system even allows for you to slip up once, but why get a chance to slip up twice. This is a lot more fair then the "team that hasn't gone to the Rose Bowl in the longest" rule that used to be in place. I understand that the schedules aren't balanced, although there will be more balance when the conference goes to a 9 game schedule. But there hasn't been balance in the past either. All conference games need to have meaning!