Personally I found the game totally enjoyable. Loved the characters, the story was very "human" almost wasted on an action RPG. On the down side , the view felt very outdated and while I liked the book format, I can't help but see my friends side of things when he called it cheap.
If you take FF XIII and its shinyness , but having one button gameplay. DS3 is the opposite end of the scale, the gameplay is absorbing, but the game is lacking in production values.
Never underestimate just how much shinyness can have people overlooking any number of faults. Especially once you step into the more general market.
I think it was the same with FO3 and FO:NV. FO:NV had a much more involving and complex story , but built on the same engine as FO3 and not having the same wow factor. Bugs never help either, but I never actually came across any in DS3 (maybe I was lucky I don't know). Unlike Alpha Protocol and FO:NV.
As an action RPG DS3 pushed all the right buttons (maybe a tad too hard for the ultra casual though) but as a game in todays market I think if you want big numbers then you need to push the production values as well. That way even if your "game" sucks people will still be captivated by the cinematics and overlook it.
Of course I have no idea of the cost vs profit of the game so it could have done well in that respect.