I imagine it could be difficult for Spyderco to keep up with smaller dealers, who purchase their knives through a distributor. It probably started out as a favor - "let us know you carry our knives and we'll put your name on our list" but if the dealer no longer carries Spyderco knives, or knives at all, they don't call up Spyderco and say "take our name off your list".
That and the tendency at Spyderco of wearing multiple hats - I doubt there is an employee whose sole job is to track currently active dealers, rather it is "one more of many tasks" a person might be involved in.
That said, it could be useful to have an updated list of dealers if it were possible to keep it current.
Which Knife, A or B? get Both
! (and C, D and E)