Sorry but comparing BG to D:OS on story etc is pointless. It's like comparing George RR Martin to Terry Pratchet. Both write fantasy but have a wildly different approach to it. While BG is allot more "epic" and sometimes dark fantasy D:OS is meant to be light hearted. If you've played any of Larian's other games you would know that as well. It's completely different styles for different audiences.. So if you were expecting an epic dark fantasy you'd be disappointed with it yes.. but again that wasn't the intent of this game from the start. So the issue isn't with the game, it's with your expectations.
Certainly, anyone who is trying to evaluate D:OS at the level of a serious story and judging it accordingly is just looking for an excuse to pan the game.