Why is there no Local Co-Op!

What has become of Halo? No Local Co-Op on one console. Why? When I first started playing halo, online was a small part of a great game. To have your mates on the same couch as you, everyone having a good time, made Halo for me. Even when I started looking into the online aspect of Halo, local Co-Op was still one of my favorite aspects. Why has 343 removed local Co-Op. Is it just a money making technique, or did they just not have enough time to include it. Either way, Halo should include local Co-Op. What is your opinion?

Feel free to use the split-screen thread if you want to discuss this further
Official Split-Screen Thread