To me, "Halo" is a lot more than a visual thing. To me, just because a game has a Spartan and a DMR, BR or Pistol doesn't make it "Halo."
Halo meant a game that was beautifully simple on the exterior but hid incredible depth in the actual gameplay. Rather than attempting superficial, false "depth" through onerous loadouts, redundant weaponry, or meaningless progression systems, depth in Halo evolved through the actual player. It was true growth in a players understanding and ability in the game.
It was pure competitive bliss and undeniable fun. It was a perfectly paced arena shooter that worked on a console. It was fast, responsive and rewarded players for making great plays and good decisions.
Now, "Halo" is Call of Duty lite, with the added bonus of super slow kill times that force complete reliance on teamshot above all else. "Depth" and a player's actual ability are irrelevant in the actual gameplay, because the core value has shifted to unlocks, perks, and loadouts.
Instead of returning to the true roots of Halo, the roots that made it the cultural phenomenon it was, 343 instead chose to attempt to morph it into some bastardized version of a different game. Rather than differentiating itself and standing tall based on fundamentally solid gameplay, they're willing to sacrifice the core concepts of Halo in a pathetic attempt at what I can only assume is a money grab.
I was honestly looking forward to Halo 4, but now, I truly think Halo has shifted beyond something I can even continue to hold out hope for. At least I have it's big brother, Black Ops 2, a week later to look forward to. If 343 is content to tag along behind CoD, picking up its scraps from 3 games ago, I might as well play the real version of it.