It must really suck to be Bioware right now. There is nothing worse than putting something you've put years of your life into out there and having it blow back in your face. I can't comment on it yet because much like a certain small bird, I've only just found the time to dig into it.
That said I can't really see why everyone would bitch so much about the end when there are things right at the start to bitch about. Like, the writing skipping back and forth between old school awesome and absolute trash. Or the blue shadowbroker woman (I don't care what her name is) reading from the script and forgetting there is the word "Acting" in voice acting. Or the fact that it often looks like it was made before Mass Effect 2 and has the worst cover system ever.
It's still fun though, because at its heart Bioware knows how to handle an RPG. It's a lot like Uncharted 3 actually, very good but the shadow of it's predecessor looms over it.