I really don't think it's the knife that's useless...
I can't speak to the ESEE customer service as I've never had the need to contact them, but I am afraid that your expressed opinion--that a knife is no longer any good in the outdoors because some rust formed on the edge--betrays such a lack of understanding of tools that you're going to have an extraordinarily tough time finding any knife that satisfies you if you actually use it, at least until you get a great deal more experience under your belt. Sailors used non-stainless knives, saws and axes for centuries in saltwater environments and, I promise you, didn't chuck them overboard as "useless" when iron oxide formed. The pioneers who settled the world never enjoyed "stainless" steel, nor did they have guided sharpeners to maintain them with. The amount of edge degradation sustained from the type of corrosion you describe probably left the knife sharper than any of the stone/bronze/iron tools man used to hunt, kill, make fires, and skin animals for tens of thousands of years, and probably could be entirely corrected (functionally, if not cosmetically) with one swipe per side on any kind of knife sharpener, the bottom of a coffee cup, or maybe three swipes per side on an obliging field stone. If you can't survive in the wild with a knife with a rusted edge, then I'm going to make the prediction that you can't survive in the wild, period, and probably shouldn't try yet without supervision.
Something else to consider---if you didn't clean the edge of vegetable matter (vine guts) or whatever else you cut with it, and just put oil on top of it, it (the oil) couldn't protect the edge. That's like putting powder on a baby's butt without wiping the poop off first. Not saying this is definitely what happened in your case, but in this era when so many are oblivious to the need to prep surfaces before finishing, painting, gluing, etc., I don't even expect most people to know how to oil things. Alcohol wipes work great. Out in the field, dirt makes for a wonderful cleaner---don't stab the ground, but take a handful of dirt (not mud) and clean any blood, plant matter, etc. off of your edge by gently swiping dirt over and off of (NOT along or into) your edge. Once any gooey/sticky stuff is gone, a few swipes on your pant leg will knock the dirt off, and then if you feel like you absolutely have to oil it, you can.
There is sufficient knowledge accumulated on these various forums to teach you all there is to know about ANYTHING knife related. I would, whether or not you decide to go all-stainless from this moment on, spend a LOT more time reading, and learning how to use your tools, especially if you're going to pay for good ones. Right now, the indignation seems to vastly outweigh the intuition, and good intuition derives largely from experience.