Yup. Instead we got a leading Templar going berzerk because of 'red lyrium syndrome'. Ditto other characters.
The advantage of black-and-white settings is that is relatively easy to set up conflicts. Go a more believable, realistic route, and the demand for quality writing - and being able to implement that quality writing somehow in the setting, characters and dialog - goes up.
Immersion, believability, suspension of disbelief, bla bla bla. They suddenly become a thing when setting and characters try to make it look as if they are 'real' and 'complex'.
You do notice I'm only making references to Origins here. DAII is not a standard either. And the situation was more complicated than that either way and you know it.
In Origins, the Darkspawn and the people of Haven were card-carrying villains. Maybe some demons too, but that's harder to be 100% clear on. Apart from that, it was often grey. Bhelen/Harrowmont, Loghain, Zathrian, Cullen, Flemeth, all these people could oppose you or do terrible things for understandable reasons. You could easily add the Architect too. In Baldur's Gate, the only villain that's anywhere near as grey that I remember is Balthazar in Throne of Bhaal. All the others just want to kill people so that they can ascend to godhood, or are just evil by default like the Drow, Dopplegangers or Illithids. That's pretty samey and boring if you ask me.
Hell, even DAII had the Arishok, a very well written villain that wasn't doing anything for the evulz of it.
And what's your point, anyway? That black and white settings are better because they're easier to make and swallow? That's a pretty lazy excuse. Even in the Forgotten Realms setting, you have have very well-written stories that aren't black and white; the Mask of the Betrayer expansion for Neverwinter Nights 2 is a prime example of this.