Well as to what I expect from Killzone 2, it gets off its high horse and stop acting like it is the second coming of christ, it is an average shooter at best.
A single weapon IS MOST DEFINITELY NOT realistic, a perfect example is wielding an anti-tank rocket launcher, even the lowest grunt would always be expected to have his rifle with him and not expected to run into the fold without a proper weapon to defend themself:
And how the hell is it realistic to issue a 6 shot revolver as a back up weapon anyway? They should have a 15-20 shot automatic pistols, no army has issued a revolver since the First World War, magnum or not it is a ridiculous weapon to issue to front line troops. Actually a far better weapons would be this that was made specifically for this scenario:
MP7 is similar weight and length as a magnum revolver used in the game, only far far more effective.
Also, Sev is not a "regular grunt" as it is quite clear he does not stick close with his platoon and rarely even stays with his 4 man squad, often it is him fighting alone, he can't say "Cover me While I go and Look for a Rocket Launcher then Get into Position to Shoot It!!!!" he has to take the initiative himself and have both weapons. He is ordered to go on extraordinary missions with very little support, if that isn't special forces, he is at least some sort of commando trooper.
Also, what is with the no under-barrel grenade launcher, it is practically standard issue in modern armies now and was even in Killzone 1, wtf happened? There are also pump action under barrel shotguns for assault rifles now, is there a new wave of minimalism taken over armies of the future or is the ISA just run by a bunch of cheap bastards?
It is also common for a sniper, especially a lone sniper, to carry a secondary weapon like a submachine gun for close in self defence. Take Simo Häyhä, A Finnish war Hero who killed over 700 invading soviet troops in only 100 days, over 200 of those killed were by his submachine gun. He also got shot in the head yet still had the presence of mind to shoot his attacker before slipping into a coma. Yes, he did all this without regenerating health or save checkpoints, history's bona fide badass.
So you ask what I want in a video game? There is the phrase "less is more" but sometimes less is quite simply less, GG removed and reduced FAR too much from the regular formula and polished it in all the wrong places. Halo was a revolution as it got rid of all the clutter of having 10-20 weapons, purifying it by forcing you to try and get two weapons to complement each other, learn how to use them in combination. COD and many other games would follow but with only one weapon as in KZ2, there is no synergy, there is no mixing and matching like shotgun up close then rifle for a long shot, you just stick to the most vanilla weapon in the game and never put it down, ie the M82.
GG seems to entirely miss the point of what makes shooters enjoyable and brings nothing new to the table.