.... Because the rest of the game sucked? The only things I enjoyed were the moving backgrounds and a few of the side character's stories, that's it. The main story is a crap from immediately demonizing TIM to adding 3rd act macguffins to squeezing all the sympathy the could out of a fucking kid just because it's a kid. The combat was nothing to write home about, it certain doesn't dwarf ME1's combat by comparison. Most of the main characters are completely overlooked offering little to nothing to the story besides fanservice-
Not even the head writer or lead composer of the original game worked on this and it shows. Not to mention the "if you're not a fan it's ok you can still buy ME3" campaign that was fucking bullshit. The way they covered all their bases for "new fans" was by adding a retarded, drooling monkey that was pointless, horribly acted and did nothing but ask stupid questions that long-term fans knew 200 hours ago.
And then there's the ending. It was stupid. 2/10