I was going to make my own post about my issues with the game, but you seem to have hit the nail on the head.
The loot system is the single most asanine thing I've ever seen, and is probably the most frustrating part about the game. Back in the day when I played Payday 2 (which I see a lot of similarities to in this game, at least in the base design structure), what inevitibly made me quit was the fact that you have to grind the same couple of missions over and over again in order to actually unlock ANYTHING. Because of the way the blueprints are currently set up, where you can only MAYBE unlock 1 per mission, this is really starting to go the same way.
Lets look at it as math. There are currently 9 unlockable weapons in the game. You have to BEAT missions a minimum of nine time. However, this number is increased because of duplicant blueprints, and also the fact that up to 3 other people are grubbing for the same blueprint. Let me arbitrarily increase this to 30 missions because of that. Each mission approximately takes 25 minutes in my experience. That's nearly 13 hours of continuous playtime JUST to get the blueprints, not to mention the coins you need to buy the weapons themselves, or that you need to unlock skillcards, new characters, etc, etc.
At its current design stage, Raiders is just a huge grindfest that I can't see myself investing too much time into. On the other hand, I really love the concept, I love the fact that the devs are making this kind of game into a story-based adventure, and I'd really love to see where they can take that.