If they wanted to portray "real" people, they wouldn't use morality to do so, as morality is nothing but fiction, and trying to define people with it will only get you that, fiction.
Grey seemingly exists in real life solely because everyone has individual will, and everything that happens is simply the result of all those individual wills clashing.
Games do not, and can not, show this. For the simple fact that they are games, trying to tell narratives, and narratives are, by the nature of being narratives, unrealistic, as the real world does not work on some developer created master story plan, it just IS. The sheer fact of having a narrative destroys any realism, and it ultimately puts the PC in a place of unrealistic power and position, and then forces everyone around the PC to bind to this same unrealistic setting, thus destroying the realism of them as well.
Trying to insert grey as a means of realism into something that is naturally not realistic only borders on the worst of armchair intellectualism, on the same level as garbage like Inception, and Lost, that try to make things more complicated then they actually are, in some vain attempt to be "clever" or "smart" or "thought provoking".
I would rather not be so intellectuality insulted by a game developer thinking that I am so simple minded that I cannot see this, and cannot see how their attempts to force realism on their NPCs, which are intrinsically not realistic due to being wrapped up in these unrealistic and over dramatized narratives, only further makes how "crafted" and "developed" and "created" they are.
I would rather games just admit that they are what they are, narratively terrible forever, and try to focus on giving the player more to actually do, rather then mazes of false choices akin to The Pitt or NV being passed off as depth.
I honestly don't get how people enjoy this, but then again, I honestly don't get what people saw in the false ending of Inception either, but apparently it was great and "thought provoking" to so many people.