Its got a lot to do with protecting the chrome too. Hoes with the traditional configuration put the rods at the top to help keep them away from debris as the bucket crowds toward the body.
I think it has more to do with the location of the hoses. They are easier to plumb up if they are upside down... That is why most of the Liebherr machines are arranged like this.
I was always of the understanding that the reason was to do with Break Out force from the cylinders.
Depending on the Plumbing.............there is usually more surface area exposed to the Piston Head on the Barrel side just as there is reduced surface are on the Piston on the Rod End due to the Diameter of the Rod????
That is how it was explained to me by some one who I always trusted as being all knowing! Any other theories.................?