BioWare is starting to be a bit more open in their thoughts about Mass Effect 3's ending. Executive producer Casey Hudson stated that much of the criticism of ME3's conclusion is valid.
Hudson starts off by saying that Mass Effect 3 itself is a "series of endings." The various storylines of the trilogy are being wrapped up before the actual end sequence. The implication here is that they didn't tell you what happened to individual characters after ME3's conclusion because you already had some idea of their future based on prior events in the game.
"We always intended that the scale of the conflict and the underlying theme of sacrifice would lead to a bittersweet ending—to do otherwise would betray the agonizing decisions Shepard had to make along the way," Hudson said on the BioWare Social Network Still, we wanted to give players the chance to experience an inspiring and uplifting ending; in a story where you face a hopeless struggle for basic survival, we see the final moments and imagery as offering victory and hope in the context of sacrifice and reflection."
He notes that that the game has received a lot of positive reactions from both critics and gamers alike. However, they're not ignoring those who disliked the game, specifically the ending.
"But we also recognize that some of our most passionate fans needed more closure, more answers, and more time to say goodbye to their stories—and these comments are equally valid. Player feedback such as this has always been an essential ingredient in the development of the series."
Hudson reiterated his earlier statement that user feedback will be incorporated in the game's upcoming DLC.
"So where do we go from here? Throughout the next year, we will support Mass Effect 3 by working on new content. And we’ll keep listening, because your insights and constructive feedback will help determine what that content should be. This is not the last you’ll hear of Commander Shepard. We look forward to your continued support and involvement as we work together to shape the remaining experiences in the story of the Mass Effect trilogy.