RJ 17 said:
When you pay for a movie and don't like the ending, you don't demand that the ending be rewritten. You write up a critique and say "Well the movie was good but the ending sucked."
When you pay for a book and don't like the ending, you don't demand that the ending be rewritten. You write up a critique and say "Well the book was good but the ending sucked."
While those arguements are certianly valid enough, and apply themselves to the vast majority of games, I think a large ammount of the reason for the ending backlash, and why they don't quite apply here is what made the ME series unique in the first place - the ability to import your choices from a previous game into the sequels and see how they effected the game. The result being a situation where you could have three different fans playing three different and entirely unique versions of Shepard, and given that ammount of choice and creative freedom it's kinda hard not to think that the story is partly yours.
And thats where the 'if you watched a film/read a book you didn't like the ending of you don't demand the ending be re-written' kinda falls apart, because outside of maybe a choose-your-own adventure book (and I'm not even sure if those really count since there's generally only one or a small handful of 'correct' paths to follow) there's no way that you, the viewer/reader has any influence over what happens. Your interaction with the media in question is completely passive - you observe someone else's work. It may evoke emotions in you, it may resonate with you, it may bore you to tears, but you have no way of shaping the narrative. Even the average video game follows this. You may have a bit more control over bits of it, but the narrative is generally fixed (via cut scenes, dialogue, etc) with very little freedom of choice.
The closest thing I can think of to how a film would work like that would be like the special feature they included on the DVD release of 'Final Destination 3', where you had the option of trying to 'defy fate' each time a death scene turned up and if you pulled it off you got an alternative scene. Ultimately this just ended up making most of the death scenes shorter, save for one bit where one of the characters actually survived, only to be shown getting arrsted for something later in the film. It was pretty crap to be honest, and its only a DVD feature, but its the closest I can think of as to how an audience can actually make choices that would affect a film's narrative.
People crap on George Lucas for the Star Wars prequels and his obsessive tinkering with the original trilogy. We all know the depths of Star Wars fanboy obsessive rage (I'm guilty of it myself at times).
Now imagine what that would be like if we'd gone through the prequel trilogy being able to choose if, say Qui-Gonn gambled with Watto for Anakin's freedom and the parts he needed, or if he'd just threatened him with the business end of a lightsabre and intimidated him into giving them away, or if, say Anakin went on his bloody spree of vengeance in the Sand People camp after his mother's death, or if he swallowed his hate and tried to be a good Jedi, or whatever. And then at the end of the film Lucas went 'no, you're not allowed to make choices anymore', introduced Darth Sidious' (and Maul's & Tyranus') unrevealled hidden master who pulled some bullshit explanation for the plot out of his arse, made Obi-Wan and Anakin fight 'because I say so', and then ended the whole thing with an advert for Star Wars merch.
The fan explosion from that'd make the retake movement look like a toddler's temper tantrum