Fascinating subject.
Rabu brought up a good point, when he refered to youngsters using guns/Bows and Arrows etc...and Imagination.
If computer games have done anything bad...it is possibly that they have stiffled imagination in (some) Kids.
I am 'reasonably' sure, that Historical type War Games, have in fact developed my son's interest in History...but certainly not on their own! (he too had the toy swords etc..that first got him into The Medieval period...and it has moved on from there.)
Worthy note....his interest in Warfare ends at around the time of the Zulu Wars.
He has absolutely no interest in WW1, WW2, or any conflicts post that!...If I show him a jetfighter game, or a WW2 shooter, he rolls his eyes, and loads up Napoleonic Total War