older resident evil games werent even about shooting zombies. In resident evil 2, the 1st 10 zombies you see should be avoided, and a few more should be knifed.
When I play RE2, I literally only shoot two zombies, knife three, and avoid all the others until the police station. Once I'm inside, I knife them when there's 1-2 in an area. Anymore, and I'm going for the guns.
There simply isn't enough ammo in the game to shoot every single zombie. It's kinda like assassin's creed in terms of how the gun mechanic works, but not as strict and broken as assassin's creed.
The newer games, like RE5 and 6 want you to shoot down every zombie you see and give you tons of ammo. Capcom feels that people don't have the mental capacity to handle the older resident evil games, honestly. They take a lot of patience and execution.