Lots of people say this, but it doesn't make it true. You are confusing a Sports Book with a Betting Exchange. They are two different entities. While it's true that some sports books due try to limit exposure by attempting to get nearly equal action, their goal is mostly to maximize profits. This means having sucker bets out there that the public will eat up and they are happy to cover the other side.
Your method of moving the line does not help once the bets came in. This just gives the opportunity to attempt to middle, with the book on the hook for cases where they pay out to someone guaranteed. Sports books will know their lines are not always perfect, and if there is too much money coming in on one side, they'll move the line because the sharp money typically will hit first and indicate where the sports book erred. The sharps can profit on smaller bets, but the big money comes in later when the lines are closer to true or still even skewed against the public.
The other part you are missing is there is no other side in futures bets like this. You cannot bet "Ohio State will not win the title" directly. You can only bet on every single other team, in some amounts, including a Field Bet. So there is no other side to move the line in this case. Not that you were even correct in spread bets or money line bets where you can take either side.