The thing that the fans have been complaining about isn't that it was a sad ending or that Mass Effect isn't a work of art. It's the fact that we were sold a product that we were told would have several different endings based on our decisions throughout the series, we wouldn't ge choice A, B or C at the end and we would get closure for the characters that we had invested time into. If Bioware had given us an ending with these features like they had promised leading up to the release of the game there wouldn't be the outrage that there has been.

@stan_boyd @Arcturuss But Mordin living or dying or your romance is the conclusion to a plotline not the story, which on the whole were all very well done and most people were very impressed with. We got to see the choices we had made in the previous games reflected on screen and make decisions that would impact the way that the genophage or geth/quarian plotlines would be resolved for example.

In the end however you get choice A, B and C which were made in isolation to whatever you had done previously, then there was no closure about the characters and the world in general. These were two very specific promises that bioware gave before the release of the game.