You don't give me much to work with here so I'll try to make a case for what I dislike. Skyrim with a teenage audience isn't a good description of the game. Actually calling it Skyrim is wrong cause there is so much difference in narrative, interactivity, gameplay etc that it just doesn't make sense. Being "open world", which is still debatable, hardly allows for that comparison.
I disagree with your negative view of the characters as well. I think they are DA's strong point and pretty much the reason to play them. There are a few problems with character development, because some of them have lower quality development unless romanced, but I can overlook this easily for both DA games.
Now for the story and setting. I think it's pretty unimaginative compared to other games. A lot of people claim that DA deals with a lot of mature and controversial themes, but the conflict always feel contrived to me and this is true for many Bioware games, so controversy for the sake of it loses it's meaning in my opinion. I can summarize DAO as an obstacle run from A to B using a zero sum policy. It's always something bad followed by something good. There is minimal personal observation, exploration, understanding. Even the main objective, which is to use the treaties, is actually forgettable. I felt more like a professional errand boy rather than a person with authority. Request help, obvious problem, solve problem, get support, repeat 3 times. Now you have an army. Go to denerim to deal with loghain, same thing. Big problem, solve problem cause Anora got imprisoned for a reason I'm not really sure about yet. If it had to do more with the fact that we are outlaws, or the factions tried to go back at their word and betrayed us etc it would feel more organic.
I keep going back to Mask of the Betrayer to show the difference. In this game, the protagonist has to deal with his condition, and this takes him to all the crazy places. You want to go there because there is something to be learned. You want to bring the right person with you because he will help you navigate. You don't even know what you expect to find there, You just take it on faith. Skyrim does this, but on a much lower scale because it's pretty straight foward. There is no duality to his condition, just the promise of power, paid with the responsibility to save the world.
DA games never deal with the internal conflict of the protagonist. It always ends being about the others. We don't deal with what it is to be Warden, or a mage, or our origin stories. We just solve the world's problems. Even Hawke, where the game is supposed to be about his story, has that problem. After act 1 which is mostly about him, you just continue helping the same people you already helped. Reason? No reason. Arishok calls you to extend a courtesy cause you killed some mercenaries for gold...? I'm willing to bet that DAI won't focus on what it means to be touched by the fade, the internal conflict. They said that specializations will alter dialogue, but will they again expand on this? I doubt it. We will probably get "Oh you are a necromancer? Cool!". Or some variation.
Dark Souls has an obvious problem, it's way too minimalistic, and actually causes people to think that it's story sucks because they don't care too much. But it's very imaginative. It's a magical tale with a lot of intrigue and failure. DA stories are medieval setting with an obvious bad guy and mostly boring magic. I can only agree with the assessment that Dark Souls is richer.
For combat DA just falls behind imo. This is what happens when great ideas come second. Playing dark souls, you feel like an artist. It's a game where your ability to observe details makes all the difference in the world. Allows you to try something different. You feel that there is always a better way. You care about things like mechanics, muscle memory, spatial awareness. True mastery of the game is beautiful and it's evident if you watch some speedruns. DA is just modifiers and cheap tricks. Once you learn them, then it's an exercise in patience.
I actually think this will change in DAI. There is something about it. It feels like the game where you actually bother with coming up with a tactic instead of finding ways to become superman. Demo doesn't really show this, but I can see the need for more active abilities rather than stat boosters. Not every game has to test your mouse dexterity, but they certainly can try and test your ingenuity. I just hope they will bother and not just stay in the comfort zone, like "encounters are balanced for a mixed party". Cause what happens if a class turns out to be irrelevant, like rogue companions in DAO and warrior companions in DA2? Then the encounter is just not balanced and it will be open to exploits.