Not exactly a tangent since the stories are most likely the defining reason people want or don;t want a new PC. Feel free to talk about this some more, i would be interested in an elaboration.
Well, since you asked.... 
I feel like the old myths and legends of Thedas should have remained old myths and legends. Making them "real" turns them from a part of the setting to a part of the story, and it eliminates a certain amount of diversity, I suppose you could say, in how you can approach characters, both from a player and non-player sense. After Trespasser, there is 0 reason to treat belief in the elven pantheon as legitimate (I honestly got the impression in the previous games that the Dalish didn't really consider them anything more than fables anyway, but DAI simultaneously indicated that they were both legitimately revered and then swept the carpet out from under it anyway). The same way, for instance, that they said they wouldn't confirm/deny the Maker, because it weakens the characters of people like Leliana, who are defined in part by their faith. Not to mention the whole "the religion was wrong and/or evil all along!" is such a tired trope in RPGs. I like(d) the ambiguity of there being no (readily apparent) holy power of Everlasting Goodness, nor the idea that "Satan" was secretly behind it all the whole time!, either.
And like I said, it's all about the present, for me. In the first Dragon Age game, as your original post noted, there was no real plan for a sequel, so everything relevant to the story was wrapped up nicely. Sure, there were still outside threats to be considered like the idea of a Qunari invasion, or treatment of the Mages, but those were just part of the setting that could be dealt with if a future game was ever made, but didn't really have to be to make the story make sense. And "mysteries" like where the Darkspawn came from or what Flemeth's deal was, similarly, weren't important. The Darkspawn were there, they had to be stopped. Why they were there was immaterial. And personally, I thought that was great.
And then starting with Awakening, we gradually saw a buildup of loose ends, and it just got more and more convoluted with time. Corfishystix showing up in Legacy and throwing everything for a loop made me interested in the truth, sure, but I feel like since then, I feel like the games have been moving in the wrong direction. It's become less and less about great heroes rising to the occasion and doing great things that will move the world into a new age, and more about fixing things that got torqued up ten thousand years ago or some such, yet just now need to be conveniently dealt with.