There are a couple parts of Halo 4 which are just absurd and impossible. The only interesting thing is the last cutscene and you can watch that on youtube. The rest is "CHIEF GET TO THE SHIP! NOW KILL THIS WEIRD DUDE!" nonstop.
Wow. I just can't disagree more.
I think the main disconnect between our opinions is due to interest in the story. If you didn't take the time to read (and try to understand) the hidden terminals in Halo 3, then you're not going to care about that "weird dude" or understand the context of the interactions you are having with the new characters.
Furthermore, the enjoyment of the campaign story is enhanced if you have read some of the Forerunner Trilogy (Cryptum, Primordium) and/or spent the time unlocking and digesting the terminals in Halo Anniversary. That's the idea, anyhow. As always, the writers intentionally lead the players into forming their own connections and conclusions in order to tie the factual information together into a cohesive understanding of the story. It's an approach that has arguable merit- especially in the context of a first person shooter- but like it or not it's one of the hallmarks of this franchise.
The producers of this new batch of games could have chosen to take the story in so many different directions. They could have focused on Earth, for example. Or the members of the Infinity making their way to Requiem. Or the Arbiter.
Instead, they chose to delve into the Forerunners. Long-time fans who have been tantalized by the drips and drabs of Forerunner information dropped throughout the series have no choice to be excited about this. It's pure fan-service, in my opinion. It was also a risky decision to focus the series on an aspect of the story which was only apparent to a smaller segment of fans: the fans who cared enough to investigate the subtleties of the real Halo story under the surface of all the the shooting and switch flipping.
So if you're only paying attention to shooting and switch-flipping, perhaps the campaign in this game is not for you. For these people, there is a wealth of fun to be had in the competitive multiplayer modes- of which there are many. "Competitive" in this game means caring enough to equip your player properly as you level up and unlock new abilities. It's a new aspect of this particular installment, and it would be foolish for the designers not to reward players who invest the required thought and effort into learning the game's new features.
Please don't think I'm saying Halo 4 is perfect or even the best installment in the series. For my money, you can't beat Halo 3 when you weigh all of the different aspects of play (campaign, multiplayer, content creation, content sharing, unlockables, etc, etc.) Spartan Ops does suffer greatly from the "hurry up and flip this switch! Oh, no- more enemies! Hurry up and flip this other switch!" syndrome. But it IS FUN to play Spartan Ops with your friends. The levels set on the recreation of Valhalla (which explain its backstory) are standouts.
Finally, I am not saying that the story itself is perfect! Every fan feels that they might have done something differently in one way or another. But the story is at least consistent across the media that 343 has been utilizing. There is an unprecedented amount of continuity between the new novels and the events in-game. And I am thankful for that. It may still confuse the hell out of me sometimes, but it's more than you will get from the average shooter.