I'm not an artist, but I wouldn't be surprised if it has a lot to do with the framing of the shot. Do we ever see Castle Redcliffe's exterior in any meaningful way than the courtyard?
Yes, we do


There's also concept art of how it's supposed to look without any technical limitations getting in the way
I admit, when I was watching the gameplay presentations from the recent E3, it was only like during the second of them when "Redcliffe Village" popped up on screen, that I realized this is supposed to be area from DAO. After all
iconic redesigns of DA2 this lack of continuity isn't really very surprising, but it also feels rather pointless, not in the least because just how radically it alters/ignores pretty much everything from the previous game.
Anyway, on the actual topic. From what little I saw and read, TW3 won lot of points with these who saw it thanks to its huge, bustling city which allegedly feels like actual city, with lot of NPCs actively moving around, doing their things and reacting to all sort of things that can happen. When forced to compete with that kind of showing DAI made poor impression because with its tiny village apparently filled with static figures, it came across as very "old style". And not in the good sense, but rather "primitive and limited", similar to reactions DA2 evoked with its portrayal of Kirkwall.
The state of Kirkwall was blamed on the limitations of DA old engine, so hopefully in the finished state DAI can actually present something better in this regard. Otherwise I fear the opinions about it may be similarly unkind.