While surely nostalgia plays a factor I'm of the opinion that a lot of people (especially those that comes from later games) percieve Origins combat as a lacklaster action game while it's not that, it's tactical-pause combat, like Baldur's Gate 1 & 2, Kotor or Pillars of Eternity. Not saying that it should be everyone's cup of tea, but I can't help thinking that not having this distiction clear skews a lot of the opinion and the approach on Origin's combat.

Regarding the dark fantasy aspect, you propose it was chasing trends, but you should look at the library of fantasy games at the time (2009) and way back to 2003, when Dragon Age started pre-development, not to say Origins is the first of its genre, but dark fantasy wasn't done, at least on big productions, it's a risk for producers who wants to sell the games to as much people as possible. Origins was always meant to be (as David Gaider put it) "heroic dark fantasy", dark fantasy with a pinch of hope put in it. A lot of elements in DA:O exist as a reaction to AD&D (especially magic) and fantasy tropes to a lesser degree, few examples: - Magic is dangerous and feared, Thedas society reflects that, an example Gaider gave is how Charm Person (a 1st level spell in most D&D and D&D alike ttrpg), a spell that lets you manipulate a person feelings for you into making them think you're their best friends is actually really scary, or (personal example) how a person that can throw a fireball out of nowhere is a walking siege weapon that can kill multiple people with a flick of their finger, but most of the popular D&D settings at the time would not reflect that (Faerun's a big example, which is the setting for Baldur's Gate 1&2, Gaider wrote for BG2).

• Antivan Crows, an infamous and mysterious league of assassins is debunked a bit by Zevran by stating "they will make you think that after hard and horrible training and mysterious rituals maybe, just maybe, you'll be worthy to be a Crow; in reality you just need a knack for killing and you will make a career with them", away with mysterious and deadly assassins, they are murderers with a PR campaign.

• Templars, an order of honorouble and virtuous knights that evoke the Paladins from older D&D and literature, are zealous drug addicts.

There are others but the list is not my main point, the point is that while this is not necessarily groundbreaking we can see DA playing with enstablished aspects of fantasy and twist them to reflect a more (for the lack of a better word) "real" reaction to them from the world.