Yeah I think it should be. While exploring the metro, running around a corner and bumping into three ghouls isn't intimidating or scary. If you run around the same corner, bumping into 30 ghouls would be. Also a better lighting system would go a long way to adding to the tension. Exploring the X-Labs in STALKER was intimidating and full of tension because of the excellent lighting system (and sound effects) that the game used. I think the new graphics engine Bethesda is switching to will improve these things drastically - eg lighting, no. of enemies, enemy behaviour, etc.
Edit: I also think the devs should come up with some new types of mutated creatures. Ones that will give people nightmares.
hmy:
:gun: :flamethrower: :thumbsup: