Oh, i don't have a problem with bad endings, but i do have a problem with endings that make all of my efforts empty. If you struggle and fail, that is one thing. But to have all you've done subverted is going too far, not for a movie, but certainly for a game. Let's remember, shall we, that games, as opposed to movies, revolve around the player. Playing a witless puppet, even if it is in retrospect, is not a good experience - unless you can redeem yourself somewhere along the road, a redemption Divinity 2 has no intentions of giving you.
Sonic is really not a good example. Its story is not the most serious or developed thing about it. A better one would be an old adventure called "Fable" (no relation to Lionhead's RPG), where the original ending has you "wake up" and find out everything that happended during the game was just a meaningless dream. The dissapointment among players was such that the developers changed the ending to a one more respectful of the players involvement in later releases.
I definitely still think Larian has shown little regard for their players when they kidnapped the storyline at the end of the game in this way.
this man speaks the truth