As an admittedly biased Buckeyes fan I think they deserve to be the one seed.  But there are a number of analysts who feel it is a toss-up between LSU and Ohio State and they make the case for putting either one on top by the slightest of margins.

So...from the standpoint of generating national interest in the CFP title game, it would seem to me that far and away the most attractive final would be between the winners of semifinal matchups between Ohio State & Oklahoma and LSU & Clemson.  

That way you would be guaranteed an inter-regional championship game instead of the possibility of another one featuring two teams from the South as we have seen with Clemson and Bama the past few years.  (Incidentally, an inter-regional championship game—with teams truly being from different parts of the country, e.g UCLA vs North Carolina—is how it was done for many years in the NCAA basketball tourney.)

If the committee is going back and forth on the seeds, I wouldn’t be surprised if human nature factors into its ultimate decision and that the members implicitly recognize what I am stating above.