To add to what Twinreaper said, most people think that Bungie, and now 343, could easily fix core problems in the game with ease. It took me a while to understand that is was much more than "turning a knob here or pushing a button there". 343ind. is attempting to offer solutions to the problems and wants that have been the easiest to fix. Remember they did not create this game or system. They are also working on their own projects in Halo CEA and Halo 4. I have seen so many posts in the past about cheating, betraying and lag (or bad host) issues. There were corrections made by Bungie while they had it that may have made corrections today even harder to implement.
Imagine it like this, I currently have 594 posts. Say I repeatedly misspelled a word in every single post and now have to take the time to go back and correct the spelling. That's a lot of work to locate and correct in every single post. Then after I finish I realize that the corrected word now changes the phrasing of a sentence, back to the changes. Then,,,,,,,,,,,,,,,,,,! I know it is a simplistic way to look at it, but it ain't easy. Hope that helps you to see the depth of the problems in "fixing" problems.