Eh... I think Mass Effect 3 is a heavily flawed game in general, the ending was just the rotten cherry on top. And that's just the game itself, nevermind all the lies prior to release.
Then there's also Dragon Age II... and The Old Republic... and Mass Effect 2... (There's a not insignificant contingent of people who think that game is where Bioware took a turn for the worse. I love it despite its flaws, but it IS flawed in some significant ways.)... and the way EA has been overextending Bioware in general.
Yes, Dragon Age III is looking pretty good... but so did Dragon Age II and Mass Effect 3 prior to release. Point is, there are PLENTY of reasons to distrust Bioware. They worked hard earning the damage they've done to their reputation.