THey kind of tried to do that with mages vs. templars, but you also had to read the books and play the previous two games to really get the full story. First game you see that mages are all right but they're not allowed to leave that tower for their entire lives. And then there's the Harrowing, which is a traumatic experience for a young person to go through.
Second game you see how easy it is for the templars to abuse their power over the mages. But then everywhere you go, the templars are proven right: everyone seems to be a blood mage. In Asunder, we see that things are coming to a boil and then the mages decide enough is enough, and they part ways with the Circles. By Inquisition everyone's tired of fighting, but no one wants to give up their side. Still plenty of mages miss the conveniences and companionship available within the Circles, even as others revel in their freedom, and still others revel in their power and basically rampage. Then you've got templars who genuinely wanted to protect mages, and templars who simply hate mages. It's a complicated situation and there is no correct solution to it. it could have been presented better, though.
In Inquisition, they definitely did this, but what about Mass Effect?
More often than not, there was little subtlety or nuance to the writing. ME1 and ME2 did this best, but there was a lot of problems still in this regard. Hell, the entire ending reframed my entire understanding of the Reapers and their purpose to a point where I arguably support their goals, but that's the exception in a game that had a lot of black and white moral decisions.
Was Cerberus totally unjustified in what they did at Sanctuary? Or did their actions create breakthroughs that might give insight and knowledge into indoctrination and how to overcome it? The game very briefly touches on the latter, when you're talking to Joker for example afterwards (there's an option where you can say that Cerberus succeeded in their goal), but more or less approaches the game from a dichotomous right/wrong standard. It affects even the character's writing and ideology in ME3 for several characters.
I personally think that my biggest hope for the series is the loss of the P/R morality system, and how it might equate into complex moral or ethical conundrums. That doesn't necessarily = Mature rating, but it does lead to things that most minors aren't mentally equipped to handle. It goes back into the Virmire decision and its ramifications as an ethical dilemma on the rating system.
Those are the sorts of questions that many of my colleagues have to deal with when they're deployed: Sometimes, getting the mission accomplished and the goal completed requires the deaths of Soldiers. And you have to live with knowing that you're ordering someone to go to their death. If you're in a bad enough position, you might even know that you're doing such.
And there is no right answer to that. You're playing with who lives and who dies. That's really not a concept that the kinds of people who can't buy a Mature game can usually handle.