I have said this many times DMC is a gameplay type of game. It's focus is gameplay.
And it has little realism in it.
If your gonna tear apart everything by DMC then you can do that with everything. Such as "It's not very realistical for a person to have white hair", or he gets stabbed with swords tons of times and he does not die despite you seeing liters and liters of blood rushing out of his body, or how Dante in DMC 1 shoots a motorcycle with bullets and it doesn't explode but gets pushed...
It's really weird how DmC is a stand alone game but when Ninja theory makes a reason for this game. A reason for why DmC world traps Dante when he meets demons (the reason being limbo), people try to apply that "reason" to other DMC games.
The reason for the spiderwebs, aura walls blocking doors/paths in DMC 1,2, 3 and 4 is two:
1) Demons appeared he was ambushed/surrounded (a logical reason)
2) Gameplay thing.