Skyrim is massive and huge and rich lore and everything but their is virtually nothing in the actual combat. So I'm sure design choices were made and some things like massive scope and lore were prioritized in over other things.
As far as BW games go from what I have played of DAI I have yet to see that fine of a level of detail. And that is what a lot of these posters are asking for right? Which is for the ME world to be made more like DAI.
You can use swords, shields, claymores, daggers, staffs, bows, crossbows, hand-to-hand, magic, whatever you want to do. There is much more variety in Skyrim's combat than most RPGs, including any of BioWare's games, so I never understood this criticism. Could there be more depth to the combat? I wouldn't mind that, but it's intuitive and engaging, which I like.
I think what people want are the perfect blend of BGS open world and BioWare storytelling. I haven't played much of DAI so I can't really judge the game, but I believe BioWare missed some valuable points for why BGS open world games are so successful. That's largely because of emergent gameplay, which is almost nonexistent in DAI. You are either doing fetch quests, going to random locales to build a camp or place a banner showing you were there, with the occasional side quest (at least that's what I got out of the Hinterlands).
The reason why BGS games are always so incredibly detailed is because the world is the story. In BioWare games, the world is just a set piece for the story, which is why I've never felt their environments to be all that compelling. BGS, the world feels lived in, there is a culture and a history there, and every place is unique and different. in BioWare games, the world seems artificial and made to compliment the story. I certainly want BioWare to maintain their storytelling edge, but I'd like to see more depth and detail into their worlds.