Point A: Horrible regimes are brought down by "vocal minorities" not "vocal majorities". Silent majorities are the ones who are battered so badly by the horrible regime that they are simply unable to fight.
Point B: There is no consensus opinion on Mass Effect 3. We don't really know what the majority thought of the game. We know a large mass of people were upset by the endings. We know a great deal of those people include us The Bioware Forum/ex-Bioware Social Network crowd.
Point C: There are no reliable data on how "good" a game is. Too subjective, and we can't get every single person's opinion.
Point D: What the fans think of the game is good enough. Don't look for what the "majority" thinks. Look for recurring critiques from both professional and non professional critiques. Get as many different point of views as possible. Then you have some reliable data to work on. Sure it's all qualitative but the quantitative data is flat out useless. It's all sales figures, polls and meta critic scores.
Point E: Metacritic isn't useless. Ignore the scores. Read positive and negative reviews from professional and non-professional critics. Metacritic is the best tool out there for determining how "good" a game is and whether or not you will like said game. Just ignore the numbers! The numbers are completely useless! The reviews are the useful part.
Point F: [The opening poster did not fall into this trap] If you have any allegations about professionals and non professionals review bombing Metacritic, provide some evidence to back up the claims. Also if you have any claims about professional reviewers have been bribed, prove it. I am not asking for proof that this stuff happens. Of course it does. I am asking for evidence of specific individuals/organisations being culpable. These are serious allegations that demand strong evidence that can hold up in court.
Point G: [The opening poster did not fall into this trap] We're not all the same. Not all professional video game journalists/critics are the same. Not all non professional game journalists/critics are the same. Not all gamers are the same. Please bare this in mind.