Dittos to what Excap said. Additionally there is another reason probably just as important but somewhat overlooked and that is learning to maintain orientation in all attitudes and light/cloud conditions.

Learning this ability seems for most to be easier with with a high wing cabin type or parasol airplane with dihedral. Visually a low wing particularly without dihedral tends to be more difficult to maintain orientation with and thats not desireable for an initial training environment.

John