It wasn't epic. Simple as. It wasn't a bad campaign, but it wasn't Halo.
-blam!- being humble,
-blam!- Spartan-IIIs they suck balls,
We want to be a arse-kicking, duel wielding, 7-and-a-half foot, green, armour-clad, super soldier fighting against impossible odds, filled with subtle humour, with a blue chick in the back of our heads and coming out the other side battered, bruised but alive!
We want to comply with established canon, we want to be the lone wolf, we want to be the only person capable of stopping the alien hordes.
Fighing as a team, and losing. That's for the poor sods you read or hear about. It's not for the main character(s). We are the hero, we are the one every looks up to, that everyone hides behind because we are the one person, the one weapon that the enemy is afraid of.
Reach has none of that, and that is why I don't like Reach as a Halo game. Noble team should have been a novel, or an accompainying cut-scene-story that played alongside the main campaign.