Ok, read all three pages, if anyone asks.
To say that "classic" Halo is killing the franchise is a bit... harsh. I would say that Halo CE stunned everyone when it released, and Halo 2 stunned everyone again because it had online matchmaking, and that Halo 3 was a "must-have" game if you liked online competition. There were real problems with Halo 3 and Microsoft and Bungie were not getting along. People were definitely becoming actually famous playing Halo 3. It kinda happened with Halo 2 but people like Walshy, Bravo, Ninja, etc. were Stars, and a a lot of people wanted in on that and invested a lot of time and energy into Halo 3. Xbox Live was also not handling Halo 3 very well. Matchmaking was really a sore spot. Most people agreed that a new game was in order. Unfortunately, Bungie and Microsoft agreed to disagree, and Bungie had to spit out two more games and then leave Halo forever. So the next game was not Halo 4. It was Halo:ODST. We played it, we liked it, and it briefly took attention away from Halo 3. But now we were REALLY ready for the next game where all the problems would be addressed. We were ready for Halo 4. We were teased for a long time, and when things began to leak about the next game we were sure it was going to be Halo 4. Some people believed it was going to be Halo 4 right up until the moment they held the disc in their hands. Halo... Reach? Why didn't they call it Halo 4? Spartan III? Three is higher than two, so a Spartan III should be better than a Spartan II, but they're NOT. No Master Chief. This is just all messed up in every possible way.
So, what we actually recall from those days is that there were three main Halo releases, and each enjoyed more good press than the last. It was a good time to be a Halo player, and a great time to be a good Halo player. Everyone concerned believed that the franchise was bullet proof. Halo had no real competition. Despite what you may hear, Reach did quite well for a spinoff. Microsoft believed Halo would work no matter who was handling the franchise. The Young Turks at 343i were out to prove that all that old school stuff from Bungie was quaint, but "today's" Halo player wanted more action, excitement, and especially, explosions. Halo 4 was so awfully silly that no wonder people wished Halo 3 was back.
I'm reminded of the cutscene in Halo 4 where Palmer meets Master Chief face-to-visor for the first time (did Palmer ever wear her helmet?) She makes a smart--Yoinked!- remark about thinking MC was taller, and Chief didn't even dignify her comment with a response. It was a silly thing for her to say, and all the Spartan IVs were really just a bunch of silly, self-centered high school jocks that had some nerve calling themselves Spartans. Not one was memorable. Not in a good way.
What people miss is going online and getting a match fairly quickly on a decent map, especially if they were looking for a tournament style game. This is why they bring up popularity. Everyone played Halo 3, but it had as much to do with nothing else out there being better as it did with movement mechanics. It's the belief that Halo 3 had somehow stumbled upon the perfect blend of movement mechanics, weapon balance and skill matching. The excesses and missteps of Reach and Halo 4 "proved" beyond a shadow of a doubt that the only way Halo survives is if it resembles the game that got the most good press. I believe what the OP is trying to say is that thoughts of reclaiming that former glory by somehow recreating the atmosphere that was present when Halo 3 was king effectively stifles any inclination to try something new or different, cause look what happens when you do that.
Now I don't believe anyone will argue that Halo 2 was not radically different from CE, and that 3 was a lot like 2. I don't include Reach because it was a spinoff. So we have Halo 3 and then we have Halo 4. Those two games couldn't be more different. Really, two completely different games. I submit that if the difference between Halo 3 and 4 had been more like the difference between 3 and two or, seriously, between 3 and CE, any disruption caused by Reach would have been overlooked and forgotten. Veteran players would have found 4 easier to accept. 343i tried to take the game where no one wanted it to go. At least, not that fast. Eventually. Maybe.
I don't think it is ever a good idea for a game to go backwards. I think they need to move forward, but in a way that we can recognize. Don't try to impress us with your ability to put this or that into the game, or make things happen just because you can. No one that plays Halo on any level wants "stuff".No one wants the ability to find the guy that killed you once you respawn (seriously, an ability that doesn't work unless you die?). People are not nostalgic about how the old games played. They're nostalgic about the attention the games got, and thus the attention players got because they played it. There is not a whole lot left to innovate when it comes to First Person Shooters. Most of what's left comes down to whether or not a player wants to wear a pair of goggles when they play. There's nothing new to bring. Just refined implementation. That said, there's no reason to have us believe the next game will be like that old game. The next game should make me entirely forget Halo 3 and the earlier games because for the first time in Halo history I should be able to play as a Spartan and no excuses because the game engine has limitations. Not "Classic" Halo. Just Halo.