MGibster
Legend
Porbably for the same reason we saw Captain Kirk fighting with the Klingons and Romulans rather than the Vulcans or Tellerites. Kirk had 99 problems, but Vulcans destroying Federation outposts next to the Neutral Zone wasn't one of 'em. Elves killing intruders encroaching on their territory, cutting down their trees, and probably littering is largely acceptable behavior. The very human Duke of Earl might do the same thing to anyone who dares to cut down the trees in his duchy without permission. Elves, other than the Drow, dont' typically raid your town and slaughter your people just because they want to take some of your stuff.And why aren't Elves the ones doing that? Elves have often been depicted as killing humans who enter their forests, so they would clearly be killing human loggers and hunters. Why are nature-based creatures like Dryads, Fey, and Elves who kill loggers who enter their territory not kill on sight enemies too?
And anyway, even if orcs aren't kill on sight, killing things and taking their stuff is still the bread & butter of D&D game play.