Your focusing too much on the problems that the games have now. And not about the what IF's for future titles. Fallout 3 OR NV wouldn't work with post MQ gameplay because they Are FALLOUT 3 AND NEW VEGAS.
Now if Fallout 4 had a brilliant story, and let you experience the consequences and impacts you've made in the MQ without compromising,any story lines or screwing over fans of the BoS or Enclave or anything like that. Would you get mad? Obviously you wouldn't you'd probably enjoy it and be satisfied. I'm not contesting the endings of NV and FALLOUT 3. I'm contesting the future of series which was the whole point of this thread in the first place. I've pretty much had everything to say.
And before you start the whole "HE HAS AN OPINION, HE MUST BE NEW TO FALLOUT!!!!!!!!!!111oneoneone"
I've played Wasteland on my fathers apple as a child, and loved it.
It's a bad idea to continue because of these things:
Nothing changes
One idea is to have nothing change, we complete the main quest and the wasteland remains the same, but the ending sliders say that major stuff did happen, yet we continue on like nothing ever did, it would devalue the choices you made by going "Oh you made this choice? And we said that happened? Well... Screw that, who cares about cause and effect?"
Endings sliders watered down
Then we have hte next idea, we have ending sliders where nothing really major happens, so that when we continue playing it will make more sense because, well, nothing major really happened, no major changes has to be made.
The problem with this is that this isn't what Fallout is about. Fallout is about changing the world, whether you want to or not, it is going to change, watering down the formula just to please those who can't reload a save is a bad idea.
Develop the changes to accurately depict the ending sliders.
This idea, is the best one on paper, but in practice it's a horror. Why? Cause it's a complete waste of resources. Instead of getting a huge game with tons of content in it we get a small game with barely anything in it and dozens if not a hundred variations of after effects they have to design.
None of these ideas are good.
If nothing changes then the ending sliders are made irrelevent.
If ending sliders are watered down then it [censored]s up Fallout's formula.
If they do develop the changes then it's a waste of resources.
Nothing good comes out of either solution.
The best solution is to either end it or have an easter egg continuation.
By ending it we can just reload a save. It's that easy, just reload a previous save and ignore the final quest.
And an easter egg continuation is fine because it doesn't matter, the ending sliders did happen, the world did change, this continuation is just a lulzy easter egg.
But allowing us to continue and see the effects made? It's a huge waste of development resources.
Instead of writing dialogue and quests for the main game they have to spend their time writing dialogue and quests for all the variations of the post-game.
Instead of spending their voice actor money on making a rich main game they have to water it out to fit the main game and post-game characters.