@John:
two reasons

1. functional
the SC20 has a nosediving tendency which is reflected in the fact that the boat nowadays only exist in a 2 feet longer version (ARC22). I think I don't have to raise the benefits of more volume in the bow, specially when its increasing the waterline length... as intended. curently the boat also generates quite some spray, something I relate to that the lines have quite some radius in the bow section, which also would become smoother if extended.

2. appearance
lenghtening the hull will stretch it lines and make it's appearance significant more elegant (personal view). and an eliptical bow, well that's really somthing from the past...