I agree that it sets a dangerous precedent, but seriously, the whole selling point of the series was that our choices would matter all the way to the end, and ultimately, 1. what mattered most was how much time we spent playing multiplayer and 2. our final options didn't line up with anything we'd seen, heard, or done in the course of the trilogy: the whole story takes an arbitrary left turn into "bluh bluh robots are evil." Which has, by that point, been thoroughly established as a dirty lie.
I'm not a fan of stupid fan theories, but seriously, the only way any of it makes sense is if we assume that what's really happening is that Robot Cthulhu psychically drilling into Shepard's skull. I don't want "closure;" hell, I don't even want a "happy ending." I just want an ending that actually follows logically from the preceding story and doesn't come off as someone's techno-luddite screed.