It has to do with weight transfer, and how you describe steering.

With the front weight, there is less effective weight transfer, so the car won't "cut" so hard getting in the corner. The weight will give more steering in a constant radius corner.

This is the same reason the SC10 4x4 guys are putting weight on the front. The truck is too reactive getting in the corner, and needs the extra grip center off. In the 4wd case, it's because the front needs more grip when you get on the power, but the same principals apply.