Okay I'm not trying to get into anything but, this is something I never get. Why exactly is it a good thing that something you probably wouldn't use nor be forced to use that other people might want to use is not included in a game?
I mean I could see being annoyed if its something your forced to use but not if you can just ignore it.
I think it's largely a matter of perspective. If you're looking at
Mass Effect purely as a game, it makes total sense to have several different endings, even lots and lots of endings, each of them very distinct in tone and intention. You play, and like in a game of chess, wherever the pieces end up is what the ending looks like, in a way.
That's not my perspective at all, in fact, I find it very unsatisfying, but it's perfectly valid and it's undoubtedly the prevalent point of view among gamers. In fact, that gamers may seen video games as
games sounds like a tautology.
It is, however, self evident, that besides being a game, Mass Effect is also a
narrative. It tells the story of Commander Shepard and his merry men fighting the threat of the Reapers. If you see Mass Effect as a narrative - a narrative that you can influence, a narrative with interactive gunfight - then it has to have proper
characters, it has to have a proper
tone, it has to have proper
themes, it has to have a proper
structure and it has to have a proper
ending. In a narrative of any kind, the ending is where you make your point, it's where you wrap things up, it's where you state: "ok, this is what's important, this is what it was all about." The ending is what makes the difference between a comedy and a tragedy, it's the ultimate authorial statement.
If there is no ending, if all you have is, basically, a series of options, then you have no real narrative, then nothing is substantial, nothing has meaning, and instead of a story, you end up with a series of loosely connected events, which is what, for me, would have been deeply unsatisfying.
And you don't have to take my word for it, Mass Effect and Mass Effect 2 both have proper endings, with lots of small variations, yes, but proper endings nonetheless without any wild tangents and variants and with a very deliberate authorial tone. I don't remember anyone complaining about that.
tl,dr: If ME3 is a game, the ending is not important and it could be anything the players want. If ME3 is a narrative, then the ending is important and offering too many options would be detrimental.