No, and here is why:
1. You state ME1 was victory through sacrifice. Why? Because countless lost their lives to stop Sovereign?
WHY IS THAT NOT SUFFICIENT FOR ME3?
Sword Fleet was never going to have it easy, they were always going to suffer immense losses - sacrifice a lot. Add to that possibly the Krogan, the Rachni, Thessia, Palaven, Possibly the Quarians/Geth - tell me where there is no sacrifice? There is F***ing sacrifice all through ME3, and we deserved a proper victory for that.
2. For you Mass Effect 3 may have been so dark, but for me it wasn't. I saved the Rachni... Again. I saved Tuchanka. I saved the Krogan, and Cured the Genophage. I arranged peace between the Quarians and the Geth. Not a single person it was possible to save was lost - except Mordin, who happily died for the Krogan. Maybe you backstabbed everyone in your playthrough, and got a dark game. Me, my game was full of hope and happiness right up until the end.
3. You fail to realise ME3 isn't a linear game. In most linear games I would support you - let the writers write the ending for their character. However, they aren't writing the ending to their character, they're writing the ending to OUR character that WE created and pushed through the world. WE wrote the story as much as they did - and this is the beauty of art in Video games. Both the Audience and the Designers are a part of the process, and both contribute to making the art. They can not be compared to movies like Star Wars, as they are nothing alike. As such, there should have been a CHANCE for a happy ending. I don't care if you had to do EVERYTHING perfectly and get the absolute maximum number of war assets to achieve it, it should be possible.
4. Mass Effect is a product, not art. There is no artistic integrity to preserve. They made a product to sell to the masses. The masses don't like their product, and now they have to either change it or not get funding for their next product. Simple. As. That. They gave up their rights to artistic integrity the second they signed on to make ME3 with EA to move sales, and not simply for arts sake - or for their own sake.
5. Leaving the galaxy a blank slate was the absolute WORST thing they could do, not the best. I won't bother linking you to all the literature articles about how much the ending fails because of this, or all the promises of closure with the endings - I've done that enough times. The endings is a blatant setup for a fresh universe in 'Mass Shift', or whatever their next Mass Effect game will be. Not cool Bioware, not at all.