hedges I guess you get more laminar airflow over the uninterrupted wing surface in a high wing config.
Smoothflier you are right of course, but there are other considerations as well. A high wing on a big transport takes up A LOT of space inside the fuselage where the spars go through. Had the pleasure of being on both the AN-124 and AN-225 and this eats up a lot of - to a passenger airline - valuable real estate. Doesn't matter much on these transports, as the wing effectively devides the upper deck which carries crew only anyway. Typically flight crew in the front compartment and cargo/service crew in the back. Plus, these things were originally designed for military use, where comfort is a second thought - at best. Add to the above access for servicing (the engines are a long way up on the ANs), and you may find that the cumulative benefit from having a low wing outweighs the aerodynamic advantages of a high wing. But, like seemingly everyone on this thread, groping in the dark here...
