There's a good reason almost all suitcases have that internal obstruction. You're limited by the outer dimensions. The bar is going to take up the same amount of depth whether it's inside or outside, but when it's inside you at least get to fit some things around it (and we actually take advantage of it--long, thin things are better protected when they're next to those metal bars) rather than have the same volume on the outside where it holds nothing but air.