I think it is obvious that Bioware's writing has degenerated, though it has little to do with the inclusion of sexual / racial minorities (despite flaws in their representation, it also helps the world feel as vast and diverse as it should be). Rather, Bioware has been failing in terms of plot, even when compared to their simple but effective plots of past games, and more importantly, tone and themes.
Looking at ME2/3 and DA2, it seems clear to me that Bioware is confused about the tone of its own story. It doesn't seem to know whether it wants to write a high fantasy, low fantasy, dystopia, an epic., heck even a comedy...etc. This leads to a contradictory mess, as we get a high fantasy epic trying so hard to be a low fantasy dystopia. Unless you're an excellent writer, such a thing is very hard to pull off and Bioware failed at it.
What's even worse is either the complete absence of thematic relevance (DA2) or themes being neglected and contradicted in the same game (ME3). Every story has to have a theme, it could be the simplest thing in the world and still be profound and poignant. When you look at DA2 and see that there is literally none, then I honestly believe that DA2 should not even be considered a story. Rather, it's 3 separate narratives (not only 3 separate plots), with the only semblance of a single narrative being Anders (who was poorly executed).
The inclusion of racial and sexual minorities is great and I strongly appreciate it (though I would prefer a more refined representation, but that will come eventually). But that's not enough to make a story.
In terms of representation, I think CDPR, if it has the will to, has a stronger potential in terms of said representation (if of course they exercise care), as they can introduce such characters in meaningful stories and complicated plots where they actually do something.