The ending was.... good, and by that mean, I'm reviewing the art and soundtrack. But it wasn't what people wanted. The reasons being because:
A) The game felt very personal, as players had uploaded their Sheppard from ME1 to 2, and ME2 to 3.
B) They'd probably paid over £100-$120 just to get this anti-climatic ending.
C) They saw a text box at the end, which is not how a game should end, promoting DLC.
D) Their war assets meant squat.
E) Bioware and EA later abandoned the "Indoctrination Theory", which was over 100 pages of case-load work by the fans.
The main reason for me was that it was a very personal journey, and that the choices I made in ME2 were supposed to do something in the final fight. But what did it matter - it all came down to a green, blue or red dialogue choice.