I think you nailed it here. Spyderco is a business and they need to make money to stay in business, and therefore need to sell a ton of knives.
They basically have three ways to do this from what I can see.
1. Continue to mass produce knives in their current lineup. But for this they need to market and sell to new distributors, dealers, customers, countries etc because most production knives arent out of stock at their current dealers these days. Their factory in Golden need to stay busy and there are only so many consumers out there who will buy an S30V PM2 so they need variety. So ...
2. Make sprints/exclusives of current knives. While this might not fill a need in a utility sense, it fills the wants of many consumers who collect knives like the PM2, Para3, Native (my guilty pleasure), Millie, etc. if there are 1200 people out there who will buy every single PM2 that comes out, it would be silly not to churn out a new model every month when that is 1200 guaranteed sales per month. Especially since there are minimal R&D costs and tooling costs compared to a new design. A lot of people say "why 3V in a folder?" The simple answer is that there are definitely 1200 people out there who would buy a 3V PM2 and another 1200 who would buy a 3V Para 3. It might not be the best choice for how most people view what a pocket knife is supposed to be, but it make sense for some people either as a "hard use folder" or as the 27th PM2 in their collection that they post on Instagram or a new knife/steel to review on youtube to get views.
3. design brand new models. this is the one where i have asked myself "why?". ive always wondered how profitable a brand new design can be if sales are slow. like how many of taiwan models and the non-endura family Seki models have sold enough to cover the costs of r&d, tooling, molds on frn models, etc? i dont believe that spyderco owns the overseas factories, correct? so if not, its not like they need to come up with new things so there is always something in production.
For me the biggest "Why" was the Caribbean line. I don't understand why they wouldn't have focused on trying to "Salt-ize" the popular Golden models like the PM2, Para 3, Military, etc. The only thing I can think of is that they already don't have a problem selling everything that comes out of Golden, so this would basically cannibalize sales of other Golden models and not really add additional revenue, but add a lot of R&D and tooling expenses. Maybe they could build a new USA Factory to churn out more Salts and more sprints/exclusives? :)
Even after probably buying (and selling 75%) over 100 Spydies to try out over the years I still don't have my "perfect" knife. For me it would be a Native LW with a DLC coated blade of 3V, 4V, or Cruwear. The Native LW Salt is the other one that would fill the "perfect" knife slot for me, but I want a blacked out version of it. I could really get by with one Native LW Salt and one Native LW in one of the other steels I mentioned and be perfectly happy and move on to other pursuits...lol. So with all of the 1000's of models and iterations they have produced over the years, I still don't have exactly what I want in an end-all be-all perfect for me EDC. I just have 25-30 that fill various roles. :)
If there is anything you should take away from my ramblings here is that I will buy any 3V and 4V Golden folder no matter how many
people ask "why"? And I bet there are 1,199 others just like me. So even if there are 7 billion other people asking "why?", does it even matter?