While yes, Spartan ops mostly reused campaign and multiplayer assets, it was fun to play through with friends and gave some background lore, and since Infinite is having an open world type of look to it, it could open up many possibilities, plus who wouldn’t want to go through a campaign as their custom spartan?
Sure. But this topic has been brought up at least two times in the past two weeks already so I’d say look in those threads and see what others think 