Project Zomboid is very effective at curbing the "Badass Lone Hero with a Cool Gun" kind of fantasy. Guns are a hinderance. They're loud and completely kill the stealth that is the base of the game, dozens of zombies swarm to you the moment you fire one. If you're an untrained person, reloading them is a hassle, even aiming is terrible (yes, I've played the 42 beta). They're heavy to carry (maybe too heavy) so they prevent you from carrying more vital stuff. Finding ammo is a pain, and this is set in the gun crazy US, I can't imagine how it must be in other countries. Even without all that, they're just very poor weapons, not every hit lands, they jam easily, you can't really use them with other weapons, you're ten times better using your bare hands.
The only way guns work in Project Zomboid is if you have an organized team behind you, covering while you reload, using tactics, etc. Otherwise, they're just a hassle. When I'm searching for loot and I find a cabinet full of guns, in any other game it would be cause for celebration, but in Zomboid I just groan, I'd much rather have found a screwdriver or a hammer, not even as weapons, as tools. (and if you really think about it, finding cabinets full of guns outside a police station or a military base is such an Usamerican thing)
The design choices that led to this are very interesting to me because it's a subversion of something that is prevalent not only in zombie media but in videogames in general: one Guy with a Gun can just mow down entire armies no problem. This is because most games featuring guns, despite all the customization options that border on fetishism (but that's something to be said about Usamerican gun culture that sees guns as fashion items), don't really show how guns are used, besides a token "press R to reload" button, all the difficulties are stripped away so the player can get to mow down as many enemies as possible. Understandable, for the sake of gameplay, perhaps, but I think that a game that shows just how difficult using guns in a stressful or post-apocalyptic situation, and in general, is an interesting subversion.