Yes, I would agree that who the "Coach" is matters the most. You bring up an interesting point. Where would Alabama be if they had RR? Conversely, for the sake of argument, how would SCUM be, and the perception of the BIG TEN be, if say Saban went to SCUM? Big "if" but if it happened Bama/SEC would be 3 titles less.
I think that when it comes to Blueblood programs, or newer programs dedicated to winning (Oregon) the right coach means everything. The same is true with basketball, where would KY be without Calipari? They were in basketball purgatory with Gillispie.
Great coaches tend to assemble good/great coaching staffs, that allow them to reel in the talent and then coach that talent up.
Geographical location is a variable though no doubt. The North's population is more urban than the Southeast. Thus, a lot of kids graviatate to basketball instead of being soley focused on football. I had friends in highschool that were being pursued to play DI football but chose basketball instead, even though they might have had a better career in college had they chose the former instead of the latter. It's the sport they loved.
Right now only one program in the BIG has the right man for the job, OSU. Jabba the Hoke might be able to right the ship at SCUM but he is not in Urban's league. The other two programs in the BIG with the potential to be a top program with the right man are Penn State (once they get back on their feet) and Nebraska. The BIG needs their Blueblood programs to rise from the ashes if they want to have the power the SEC now enjoys. We shall see.