First of all I would like to say that there is a difference between camping and defending a well travelled area by setting up a "kill zone".

the "kill zone" tactic is shown well in the end of SPR, where the Rangers/Paras expect the krauts to come down main street and therefore stack all their defenses to provide overlapping fire into that zone.
Another example is at the end of Dirty Dozen, the MG at the "donald duck" position is set up to turn the road into a kill zone.

Camping is more like when one who is not particularly skilled does something like hide behind a door in a low-moderate traffic area and shoots passerbys in the back.
Interestingly enough I was accused of camping on Crow King's Forlorn Hope in Destroyed Village when I was defending the house in the middle, the axis were trying to use the passage under the house to get to our spawn, so they could camp, how ironic that they called me a camper eek: