Hey! I was going to put up a thread like this!
Ok on the more serious note, to be honest I don’t truly know either, though I can take a guess at the reason.
Halo’s roots lie not in role-based shooters or loadout based shooters, it lies in Arena-based shooters and that leaves a lot of expectations. I’m talking the likes of Quake and Marathon, this is the sort of shooter experience Halo originally was, equal starts in arena based maps, the same weapons, basically all the typical supports of an arena shooter.
Halo 3 was proberly the last Halo to show its roots as an Arena shooter, then Reach came along and changed Halo’s DNA, whilst it held much as an Arena based shooter, the few changes in the DNA such as armour abilities (which I have no problem with) dissatisfied the older population, who went back to Halo 3. Halo 4 took a step further and had its DNA mutated further by plugging in features from other popular shooters, such as Loadouts from COD. And to some people, they took a lot of Halo DNA out at the same time. So they left again and that’s why it’s so unpopular, it’s got to much DNA from a game that does not bare one name: Halo.
In simple words, most people think Halo 3 is truly a Halo game, whilst Halo 4 is just a hybrid from a marriage between Halo and COD. Halo 3 offers true arena based combat while Halo 4 doesn’t, even though customs can be used to make Halo 4 arena based, it’s just not enough to some people.
AKA, nostalgia, tradition, skill and other simple, equal reasons are what some people want for a Halo game, and the apperent lack of it is killing Halo 4 and reviving older games like Halo 3 and Reach.
Don’t get me wrong, I personally think Reach was the best Halo to date. It was the most balanced in almost every way. It wasn’t bare naked like Halo 3 personally was, but it wasn’t overweight with content like Halo 4 is.
As for percentages, I say Halo 5 should be 60% Reach, 30% Halo 3 and 10% Halo 4.
That’s my opinion any way since I represent the smallest minority, Halo Reach