Why can't Hollywood use the actual college campuses depicted in their films?

"In the span of two days in October, Agnes Scott College became Emory University, Georgia Institute of Technology, Grady Hospital and Harvard University for the upcoming motion picture Bobby Jones–Stroke of Genius."

I can understand not being able to use Harvard's campus due to geographical restraints, but both Tech AND Emory are within 15 minutes of Agnes Scott!

It was the same with Big Fish-- film crews used Huntington's campus, a small school in Montgomery, Alabama, to portray scenes set at Auburn University, just 40 miles down the road.

It just seems shameful to pretend Agnes Scott Hall is actually Tech Tower, or that some Huntington building is Samford Hall, when the real thing is so close.

Although, I do think it is cool that Agnes Scott has a Gaines Chapel.

And it was fun to read about the various misadventures of the "T".