Sorry man, hate to tell you the series original writer Drew Karpyshyn, the guy why initially MADE Mass Effect had nothing to do with 3.SecretNegative said:No, Bioware didn't betray you, they just had a different vision of what the story needed than you had.
Even worse, the reason the ending of 3 feels so out of touch with the whole game is because Casey Hudsen and Mac Walters wrote it themselves without any input from the rest of the team. This was confirmed by Patrick Weekes, the guy who wrote Tali, Blasto ect. The two of them wrote in in private and and prevented anyone else from reviewing it. In fact if not for Patrick Weekes input, the Normandy would have blow up, and all your squadmates would have died without a single word of closure.
sauce: http://www.ibtimes.com/articles/318210/20120322/mass-effect-3-ending-spoilers-bioware-forums.htm