Yeah it makes sense from a story perspective, but from a gameplay perspective it felt like the level designers were thinking "Here's 2 warthogs for you if you're playing co-op, but if you're playing single player then **** YOU, you're on your own". It's not that big a of a deal to be honest, but it's symbolic of a lot of little issues that Bungie wouldn't have allowed. I got the feeling 343 looked at a couple of the levels from Halo 1 like two betrayals and Halo, and thought "people liked fending off waves of enemies and following waypoints to flip switches, so let's give em more of that" all the while not actually knowing how to create good, original levels themselves. I'm not asking for a Call of Duty style rollercoaster setpiece tour, but it felt like it was seriously lacking exciting moments like in Halo 3 where you and a bunch of marines are riding around rocketing a giant scarab.
Instead of anything fun like that, all I got from it were dull, hollow imitations of Halo 1 style levels, but not pulled off as well. It also felt too serious and lacked the soul of the past games but it's not suprising considering 343 are an essentially souless studio who only exists because Microsoft don't know how to let a good series of games die with grace, whereas Bungie actually liked to have fun and it showed with all the dialogue, easter eggs and humor they put into their games. I guess I just never really cared about the serious side of Halo, I was always more of a fan of the crazy **** grunts would say and sargeant johnson etc.
Then again, I felt that way about Halo Reach's campaign too, but atleast the levels were all quality, can't say the same about Halo 4. I will say though, the actual gameplay and the feel of controlling the Chief is better than ever, it just feels right. Maybe I was just expecting something more from the campaign. I do have hope Halo 5 will be better.