Less wing load is what we want. But it is not everythnig. In most of the cases the the 100cc and 150 cc class planes have more wingloading then 50cc class planes. But they fly much better and even like foamies. Why is that? It totaly is due to the volume of the airplane. Think of the plane as a ship floating in the air instead of water. As the plane dimension become bigger the total volume of the plane grows not only the wing area.This means the density of the plane decreases. And it is not the wing only that makes a lift. The plane floats as a whole.This means more lift. And that is the answer to your question. As the plane grows the wing loading increases but the density(weight/cubic inch) decreases. So wing loading means a lot but not everything.