It was never a fear of zombies or monsters either, it was a feelng of helplessness. In the old RE games you weren't really afraid of the monsters themselves, you feared how you were going to survive them with your limited ammo and health. When RE4 switched to a more action approach that fear was lost.
This, so much this. Don't get me wrong I really like RE4 but it's just not the same anymore, and got much worse with RE5.
This whole fear of feeling incapable to properly fight the monsters is what makes Amnesia - The Dark Descent so great.
Except Resident Evil was never like Amnesia in the slightest. I personally got through RE 1-3 guns blazin' like I did in RE4, the difference being that in RE4
aiming actually works.
The fact that we deal with more then 4 zombies on each screen is actually *good* in my opinion - what Capcom needs to work on is storytelling proper level design and environments choices. RE used to be flooded with claustrophobic environments, and a village in the middle of nowhere doesn't exactly fit that description (I'm talking to you, RE4 and 5).
Revelations seems to be doing it "right" due to the restricted area of the ship and tight corridors, let's hope that RE6 will do the same with narrow passages and some in-door action.