I never listen to any audio or watch any of the movies when I play. Why not have the install option of full install and custom install without all the extra audio and video.
Also saves hard drive space.

Hard drive space is dirt cheap these days (Quick search result (http://www.newegg.com/Product/Product.aspx?Item=N82E16822145287)) -- if adding the option to skip movies took even one programmer day, it would be a day wasted, IMO. That said, I'm sure CivV will be moddable enough to remove those things if you're still churning on a 13GB hard drive.