People being a general reference to the people on this forum I've seen post about DA:O being dark. I appreciate that you (and Xetykins) feel that DAO had other 'dark' content in terms of portrayals of poverty or social injustice. I personally wouldn't label that as 'dark' vs. DA:I being 'light' (or whatever the counter-term would be), because I see DA:O as more the default portrayal and DA:I moving away from it (largely because DA:I is all about people in power, and DA:O isn't).
Well, I didn't originally frame my argument as DAI being 'lighter' so much as it being 'tamer'. But I don't think it can be completely excused just because it deal with the higher strata of society. After all, so did the HN and DN origins, The Arl of Redcliffe, A Paragon of Her Kind, and The Landsmeet.
Still, I think it's really notable that when we're talking about DA:O's darkness, we're talking about origin stories. Your examples go to the CE and HR origins. Gwydden talks about the DC origin. But what about the game itself?
The origins are brilliant, IMO, but they're very much not the kind of writing DA:O then focuses on for the rest of the game. Honestly, I think they're the product of the fact that Bioware was completely free from writing their usual B-movie epic plots, much like how ME2's small vignette missions were good because they were bogged down by the B-movie main plot.
This is something that's an issue with DAO in general. The main plot is as bland and generic as it gets. Its saving grace are its subplots. Personally I felt A Paragon of Her Kind and The Landsmeet were better and more daring political plots than Wicked Eyes and Wicked Hearts. You had a larger, more questionable range of options in The Arl of Redcliffe, The Nature of the Beast, and The Urn of Sacred Ashes, although that can be partly excused by DAI placing you as a religious and political leader. Not a great move in retrospect, IMO.
And it's not just DAO. DAI was also tamer than DA2. Even though the Mage-Templar War hadn't even started yet, I found it a much more horrifying conflict in Act I and Act 3 of DA2. And Act 2 of DA2 was about the best the main plot of a Dragon Age game has ever gotten, and that's got all to do with the Qunari and nothing to do with Leandra.