Maybe Spartan-Ops can be repetitive, but you can't complain on Campaign being not fun. Fun is subjective. Fun could mean easy to play to someone, or it could mean demanding.
How can 343 fix something that is "not fun", in your opinion?
And by the way, there is a Legendary ending. Short, and in my opinion very bad and not required, but there is. So stop whining like a 3 years old and play something else, or just grow up and discuss what you didn't like about the game without talking nonesense.