So... you want all Halo games to be exactly the same with no new gameplay features at all? Isn't that what we mostly criticise Call of Duty for, yet most of the Halo community want their series to be like that? You're saying that people who like Reach and 4 aren't true fans? That or maybe we're just able to adapt. Variety is needed so that the series doesn't get repetitive. I guarantee if they made Halo 4 exactly the same as Halo 3, people would complain about that, because 343i would be showing no creativity or effort to improve the game. Whilst I do agree that CE and Halo 3 are the best in the series (not so sure about 2), Halo 4 is still a decent game, it just lost its charm pretty quickly because of a lack of incentive to keep the player from coming back.
Don't get me wrong, I would like another classic arena-styled game but if the next Halo game was an improved Halo 4, I wouldn't lose any sleep at all. Halo 4's not my favourite and it's not because it's different. It's because it lacks replay value and I feel the loadouts aren't well-balanced because of being able to spawn with a Plasma Pistol. I'd like an improved Halo 4 just as much as a classic arena-styled game, and you saying that everyone who disagrees with you is not a true fan, but I'd guarantee if Bungie did the exact same thing, everyone would love it. I could argue that YOU aren't a true fan because you're not able to adapt to new gameplay.