Will you guys give it a break? There's three factors that can simply answer why Halo 4 is not played as much as the other tittles, which are the following:
1) Preferences. People rather play other stuff nowadays, mostly Call of Duty if you ask me.
2) New management, new trilogy. C'mon, 343 are not magicians.
3) Lack of acceptance and/or open-mindedness.
Instead of being all sorry for not having the game the way y'all imagined it, just simply accept it the way it is, and hope the next one will improve. That, or just don't play it.