More Fun To Compute said:
Randomness is used to simulate complex systems. Because so many natural phenomena are normally distributed then randomness can simulate them pretty convincingly. The chance to miss a target when shooting is one thing that can be simulated randomly. Although if you just want to play a superhuman marksman with a perfect railgun that can one shot kill everything then complexity like that is irrelevant.
Except if it was actually simulated (and don't pretend like it can't be), the act of aiming would be more difficult. Scope wobble, ballistic trajectories on bullets, imperfectly aligned ironsights, drastically reduced sensitivity when aiming down sights and so forth would all be present. You wouldn't be able to line up targets with superhuman precision then be forced to wait 9 seconds while the cone on your gun slowly reduces, despite the fact that your character is
clearly aiming right at the guy's head.
In Alpha protocol, the act of aiming is very easy, but aiming properly doesn't mean crap regarding whether or not you're going to be able to hit your target, which is annoying. No amount of player skill can overcome it, making it
frustrating. Note that people generally don't complain that there is conefire when not aiming, which is itself a randomized distribution of bullets.
Now, expectations are of course important. If it looks like a cover shooter, controls like a cover shooter and you're in cover, shooting people, then the fact that it plays like a dog turd compared to others in the genre does matter. The game doesn't suddenly, miraculously become "fun" because you say "lol its rpg not shooter". If the gunplay in other (extremely popular) games is better, then it's better, regardless of any reasons for why you have chosen to deliberately make the shooting in your game less fun.