Jim Tressel was fond of calling Ohio State's quarterback the most important person in the state of Ohio.
The governor was distant second. Urban Meyer called the offensive line the heart and soul of a football team, which if you put those two together places the state's most important person right behind the identity of the football program.
They're both correct. You have to pick your priorities - if everyone and everything are important, then no one and nothing are important. It's quarterback and offensive line. Defense Wins Championships only works if it can stay off the field long enough.