Add new weapons, vehicles, and equipment to the game? There was NOTHING wrong with equipment in Halo 3. They were pretty fun to use(Power drain and Bubble shield in particular) and they slightly mixed up gameplay in a good way. Plus Active Camo and Overshields as pick-ups were perfect. Halo 3 introduced us to amazing weapons like the Spartan Laser and fan favorite vehicles like the Brute Chopper, Mongoose, and Hornet. For us, that was enough to keep us satisfied for five years. So why do we need crappy armor abilities like forerunner vision(*facepalm), random weapon drops, classes, and Spartan Points/cR?
Wasn't everybody happy with the original Halo formula? So why mess with it?
And on a side note, i'm all for Spartan Ops. The name is fine, I don;t know why people are complaining. Firefight(Particularly Reach's variant) was mediocre to me, but weekly FREE co-op missions that actually tell a story? Yes please.