The reason I'd only want bandits isn't because I'm some misanthrope that thinks that everyone would be implacably hostile in a post-apocalypse. It's actually because I think that the minority of people who would be like that are the only ones that can be realistically portrayed. In fact, it's not so much wanting bandits as conceding that, unlike the majority of people, the bandits could be done in an acceptable manner.
The thing is, people build communities and work together. When I play a co-op game with my friends, we build a base together and live in it together and share duties such as base repair, resource gathering, scavenging, and so on. It's what people do.
But for some reason, whenever the future systems for NPCs are hinted about there's never any concept of that sort community bullding. There's never any talk of the player being part of (or preferably - since you're the protagonist in the game, after all - leading) a community.
Instead, the talk is always that there are pre-existing communities ("factions"), but that you as a player are excluded from them. Instead of living with a bunch of other people and working together in communal defense and survival, you're not allowed to be part of these communities and have to live on your own. There's talk of being able to "stay the night" occasionally for an exhorbitant cost, but without that cost they'll happily kick you out and watch the zombies eat you.
But it's all totally - and immersion breakingly - unbelievable. If these communities exist, why aren't you part of one of them? Why are you forced to live outside on your own and fend for yourself against the hordes?
And if you are excluded from these communities and not allowed to be part of them, why are you trying to gain "reputation" with them and why are you doing "quests" for them?
It doesn't make any sense. A community benefits just as much by having an extra member as you do for being part of it, so why do they throw you out every night to survive on your own and why do you put up with that behaviour yet keep going back to interact with them?
I realise that the whole "faction" and "quest" system is a staple of the CRPG game, but that doesn't mean it's the ideal set-up in all scenarios; and it just doesn't fit this scenario. It's a set-up that works for the heroic-adventure genre, but the devs are trying to shoehorn it into the survival genre.
If there are going to be NPCs in a survival game - and don't get me wrong; I'd rather there were - they shouldn't be following the CRPG-esque faction-and-quest mould. It just doesn't fit.
Instead they should join with you (or you with them, but as I say; you're the protagonist so it makes sense if you're the leader or work your way up to being the leader). You shouldn't be visiting communities to trade and then being kicked out before nightfall to survive or die on your own. You should be living with them and surviving or dying together.
And I'm not chasing pie-in-the-sky unrealistic scenarios here. For example (and this is just off the top of my head, and would need refining), here's an NPC system that I'd find far more realistic than the hinted-at faction-and-quest system:
Occasionally (about once a week or so) an NPC would come in your direction - in the same way the wandering hordes do. The NPC would randomly be either (a) hostile, (b) neutral, or © friendly.
Hostile NPCs would be the rarest, but they would attack you on sight. They might attack you individually, or they might call in a bandit ambush (like a screamer calling in zombies). As I say, these would be the rarest type of person; but they would exist often enough to make you wary of just enthusiastically running up to any wandering person you met.
Neutral NPCs would work like the traders currently do, and would replace the fixed taders. If attacked they'd fight back, but if approached and spoken to they'd give you a chance to trade before they move on.
Friendly NPCs would want to join your community. By interacting with them you would be able to give them a role. The default would be "posse", in which role they'd follow you around and fight zombies with you, generally acting as bodyguards. They'd go with you when you went scavenging or gathering resources, and would watch your back while you performed those actions. You would also be able to lead them back to your base while in "posse" mode and then once you got there give them other roles, such as "farmer" (they'd stay in the vicinity of where you gave them that role; planting crops, harvesting them, and cooking food), "guard" (similar to "posse" but instead of following you around they'd patrol the vicinity of where you gave them the role), "gatherer" (they'd stay in the vicinity of where you gave them the role, chopping down (and re-planting) trees for wood, digging stone, metal and clay), or "engineer" (they wouldn't build new structures, but they'd wander the vicinity of where you gave them that role and repair any damaged structures or traps they found using resources they found in containers in the area).
You might even want to extend it to things like a "smith" who would make weapons, armour, and ammunition.
Of course, all the NPCs would need to eat, and all would defend themselves from zombies (but only the guards would be pro-active about it).
That's the sort of thing I'd find realistic. You building a community with other NPCs that you come across, and working together with them for the common good. I'd absolutely love it if a system similar to that were in the game.
But the system where you're on your own - and all the NPCs are out there building a community without you, keeping you out and making you fend for yourself like some kind of pariah, yet you're expected to keep going to them cap-in-hand to do quests for them in exchange for hand-outs and you're supposed to care about your "reputation" with them despite there being no prospect of you ever actually joining them and moving in with them (and, God forbid, rising to a leadership position within them). That I find believability-breakingly unrealistic.
And the current implementation of traders is a microcosm of that, which is why I dislke them and avoid them. The fact that you're struggling to survive against the hordes, and they've set up a shop seemingly without a care in the world; yet they won't join you for mutual protection and you can't join them for mutual protection stretches believability to breaking point, and then when you add that their shops are 100% zombie-proof (and you-proof) and will automatically teleport you out at night, that's even worse. Yes, I know it's for gameplay purposes, but the fact that those things need to be in for gameplay purposes is a symptom of how the traders don't "fit" in a survival game.
So it's not that I don't want there to be any NPCs other than hostile ones on principle. It's that I think that the current plans for implementing non-hostile NPCs - based on the hints we've had about those plans - are terrible. And I'd rather have no non-hostile NPCs than terribly implemented non-hostile NPCs.
This is why I'm often vocal about hoping that the faction/quest system will be limited to Navezgane, so I can continue to play on random maps and ignore it.