Truthfully my issues with DAI were twofold:

a.) the characters were good in typical bioware fashion but overall I found them less interesting than the characters in the first two games (except for Dorian and the Egg, both of whom are my Bros) (Varric doesn't count and I liked him better in DA2 anyway)

and

b.) the gameplay mechanics were solid but they stripped out a lot of the real oldschool CRPG stuff that was one of the major features of the first games (particularly DAO) that I liked

In other words DAO had my favorite gameplay, DA2 had my favorite all around characters, and DAI just kind of comes up short in both of those departments to me. Not to say it wasn't a good game - it was - but overall I prefer the other two.