My guess:

1) SR-101 (with bussekin heat treat) has shown that it does not fail in said applications.
2) Buying in bulk helps keep price to performance in check (ie: ScrapYard leverages production runs from Swamp Rat)
3) Do we need reasons? Dan offers one of the best, no questions asked warranties in the industry. USE the knife.

Welcome to the Yard. I think you will find there is no answer to your question. This is like asking why doesn't Busse license it's INFI formulation to others...or, do they, while require that others use a different naming convention (oink).