I have 2 inches hanging off the front of my bow for a couple of reasons:

1) Arrow durability - The little bit of extra length neccessitates that I use a stiffer arrow. A stiffer arrow is a more durable arrow.

2) Heavier arrows - It is easier to find the heavier arrow weights that I prefer in a stiffer arrow than it is with weaker arrows.

3) Close range point of aim - Shooting "instinctively", the extra length on the arrow makes it easier to see the arrow in my periferal vision, particularly for close hunting distance shots.

4) Arrow Salvage - Finally (an this is a minor point), if an arrow breaks off right behind the point (most common break with wooden arrows at least), I can retaper the broken end of the shaft and still have enough length to use it for stumpshooting or squirrel hunting.