They had to come up with something important enough to mobilize a Spartan and 4 ODSTs so the mission had to be important. The story of the episode can be summed up as: dropped on a planet, shoot some guys, fight a brute, death of the Spartan, score a headshot.



EDIT:
I'm with SW here, the mission sounded important enough, the point was to slow down, you can't replace a prophet like you can replace grunts.

...and the only thing we care about is the beautiful headshot.

I'm still kind of dissapointed there was no Gainax field of flowers scene.

We shoot aliens and we're happy. We don't care for flowers.

Who are you referring to with those "we"'s?

Um, majority of gamers? You can check me for symbiote I'm clean.

He's really the King of All Cosmos.