Rant you say!?
It's interesting with Spyderco. I love them, I own and use several, but I love the ones I have mainly because they are just minimalistic, bare bones, extremely well cutting folding knives with excellent blade geometry and functional handles. That's the "designing in the dark aspect" of them. Then we have the things many people know Spyderco for, their genuine innovating contributions to the knife world, the round hole, the pocket clip, the different locks, the spyderedge etc. Those are things that didn't exist before in the same way, but people would manage anyway, because they would simply handle things in other ways. If you really need a knife for serious work, you can carry a fixed blade openly, which makes up for most of the advantages a modern folder has over a traditional slipjoint. Then if you want to "EDC" a knife comfortably that you use rarely and for small tasks, a slippie is generally all you really need. A lot of the things Spyderco do aren't crucially necessary, but they do them anyway, just because: "what the heck, let's try this stuff out and if people like doing things this way, let's go in that direction and develop it further and make it the best it can be." and a lot of good things have come from it.
If Spyderco didn't exist, things would probably be a bit less convenient and I just hope I would be able to find another company that make knives that are that fricking good. I like that Spyderco aren't really into the whole "overbuilt" thing, that's why I'm not much into ZT anyway. If Benchmade would somehow fill Spyderco's niche, I might go there more, or I might just use more traditional, cut centric folding knives. I like A.G. Russell's traditional style folders.