Well, there was an on-going war between L4D2 and KF1 back in the day, and I never quite understood why. Besides being zombie shooters, the gameplay really isn't the same. And KF2 further cemented its differences... It's almost arcade-like really ! Score is probably not as important as survival, but the goal is still very simply to kill everything that moves up until the final boss. It's a simple formula that has a lot of charm.
For that reason, I also find the Payday 2 comparison a bit weird. But the most puzzling is the roguelike one... A roguelike is a game where you usually progress across a single playthrough, with potentially some unlockables that persists in-between matches. XP has nothing to do with it, unlock with most RPG subgenres... Precisely because levels are irrelevant, as you come back to square one when you start a new playthrough. KF2 has nothing to unlock, except for cosmetics (that you can't even control except for rare exceptions). And you don't really have any randomness factor either : there's a sense of progression, as you buy more and more weaponry to fight tougher and tougher opponents. But you get to choose what you buy ! Also, having XP that lingers and improve your character (or classes/perks) isn't really enough to classify as "RPG"per se. Tons of games introduced this kind of progression to keep the players coming for more. Is Call of Duty a RPG? If it isn't, why can you create different classes (fitting different roles) and earn XP as you play, which unlocks new gear? Is Bioshock a RPG? As you progress through the game, you earn new powers, new weapons, new skills...
As for not receiving any new update... Well, it's bound to happen at some point. Some of us (myself included) would have probably expected (or wished) for it to happen a little sooner actually, as content creep is a major problem nowadays. And it's not a fatality at all... New games keep coming all the time, and I'd be curious to see what Tripwire has in store for us ! It's typical for game devs to step to a new project once they get tired of an older one, which in turn allow creativity to flourish. It's easier to be motivated for something new than an older project. And easier to start from a clean slate than try to come up with something new for something you already worked on for ages.
And to answer to
@o2xVc3UuXp0NyBihrUnu : realism in games is far past its prime. If anything, I believe players got tired of them a couple years ago. And possibly even more so when mixed with zombies (which were absolutely EVERYWHERE ten years ago). But I concur that they overdid it with KF2... I much prefer the b-movie feel of the first game : the atmosphere, the monsters, the gore are all pretty bleak and scary. But it's still kinda funny as your character's banter is ridiculous and cheesy in the best kind of way. Some weapons are also equally ridiculous (the Buzzsaw Baw, the L.A.W. and so forth), and same for the skins. It's kind of what makes B-movie great : silly elements in a serious situation.
I wouldn't agree that it's a horror game, however, because it ain't meant to scare. Even in a game where you kill dozens of monsters like in Dead Space, the game is scary because your resources are scarce. Because you're fragile. Because you rarely know where the enemy will strike. Even KF1 had none of that. The only thing that links it back to horror is its atmosphere... Which is already pretty great, admittedly!
But personally, I believe there are far more reasons as to why people quit Killing Floor 2 :
-Content Creep
-Hell on Earth being too easy for veterans
-Lack of interesting new stuff
-Better options elsewhere (as in : other games)
-Selfish players
-Simply being "too old" (which combines the "better options elsewhere" and "lack of interesting new stuff" arguments, somewhat)