Killzone 4 was perfectly impressive.
However, despite frequent claims that diminishing returns aren't real, and every new generation will look 1000 times better than the last... diminishing returns are real.
The 7th generation of game consoles invoked modern PC style technology. Combined with maturation of development tools and graphical techniques, the result is pretty obvious: 3D games reached sufficient quality so that 3D graphics look "good enough".
You can add better textures, more physics, larger scale, more lens flare and more dirt on the camera. But generally speaking, nothing is going to "wow" people like the 360 and PS3 generation did - going from still-crude 3D visual technology to sufficiently advanced textures and shader effects, good normal mapping, good lighting, and so on.
From here on out the game is not about graphics. Graphics will steadily evolve and improve. But Sony focused a great deal on everything PS4 offers besides graphics, because that's what matters next. Connectivity, services, and new ways of playing games - something like the instant system suspend and resume will have a bigger impact on the way people play games than better graphics. Not to mention gameplay broadcasting, in-line video recording, etc, etc.
You don't have to want Zelda to be something it isn't. That's why other games exist, like Dark Souls, this one, and whatever else that is a different style of fantasy.
Sorry, I've just never understood the desire to have all games be remade in the image of the latest cool trend. Right now it's super gritty dark western fantasy where the main character desperately struggles to survive in grim dungeons. That's cool, but not every game has to remake itself in that image.
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