No, it isn't. NPCs are not uniformly available for XP and robbing in D&D. So, saying you can complete quests before murdering everyone you meet makes absolutely no sense in D&D, both from a mechanical and an alignment point of view. It's absurd, as I said.
Once again you are actually conflating entire different issues.
Also, his question wasn't "about D&D" in general. It was about this game specifically.
