Couple that very good point with the fact that it's been a wider problem for the B1G. Go back about two years and start analyzing bowl matchups from 2002 onward, and you see the B1G consistently playing better teams in bowl matchups. Sometimes that was the result of the SEC or Big XII/Pac-12 putting a team in the BCS title game, and sometimes it was a result of how well B1G teams travel in general. Regardless, the B1G often found itself in games it had no business playing.
Secondly, the B1G and OSU were slow to adapt to new offenses, slow to pay for better coaches, and generally late to the reality that CFB has become a talent and dollar war. The league has mostly righted the ship, though Purdue, Rutgers, Nebraska, and Maryland are still a basement below the cellars of other P5 leagues.
The bowl record of OSU is spotty, but that's for a lot of reasons that transcend "were they angry or not." Correlation, causation, etc., etc.