Choice in the Mass Effect Universe

Bitmob has published an interesting editorial that makes the argument that reaching different, less-than-perfect conclusions while playing through Mass Effect and Mass Effect 2 can offer a more fulfilling experience than taking the "perfect" route.
It's something I've been trying to come up with ever since I lost three.errr.two of my most trusted comrades in the midst of my suicide mission. For many, multiple playthroughs that follow specific guidelines can "right" any "wrong" decisions. If you look at the game's Achievement list, BioWare even rewards such behavior.

This could merely be a way to add replay value to a game without multiplayer, but the point remains: Why should I feel compelled to finish this chapter in an ideal way? I mean, it almost plays better if the whole thing is actually tragic. It feels like that's what the game was building up to it. All of the characters talk about giving their lives for the cause, and yet it seems like most people want to get the same ending as everyone else. Doesn't that effectively take my 50-hour time investment and throw it to the Vorcha?

These are tough questions, and I honesty can't answer them. But it baffles me that the people who say they want nonlinear games are the same people who always try to get the most "perfect" or most "complete" ending.