Lets see.
Plan A
Lets make a game using a turn based combat system that we know everybody hates and scrupiously follow the lore of that game. We will make the few thousand peop-le that actually liked fallout 1 and 2 happy but we will go broke because the game will be crap and no one will buy it.
Huh? Where did you get everybody hates turn based combat systems? There have been MANY turn based games that have been successful. Final Fantasy Tactics, X-Com, Fallout 1 and 2, Jagged Alliance (JA3 is turn based as well if I'm not mistaken), Front Mission....And something that should be noted that of these, the one that has had many real time attempts to capture the essence of the originals have basically all failed, which is X-Com.
Plan B
Lets make a game that trades on the name of the Fallout franchise but pays only the slighest attention to lore, because nobody ever played those games anyway. Lets use our current engine and our experience with Morrowind and Oblivion to create an open game in a similar style, because we have sold millions of copies of those two games and we know the formlula will work. But, if we do that, half a dosen zelots will stalk our forums pouring out hate and vitrol because we failed follow the mechanics and lore of the prevous games exactly. It won't matter though, because they will have bought the game anyway, so we already have their money.
This is just insulting. First nobody ever played those games, they wouldn't be as favored as they are! And it's hardly fair to compare Fallout 1 and 2's sales to the much more recent Morrowind and Oblivion, since the market has grown considerably in the decade since the last numbered Fallout game. And just because a game sells well doesn't mean other approaches won't either. But it's clear you're not even reading peoples complaints about the game. While there are a lot of us that would like it to be turn based, that's not the focus of our complaints. It has to do with the game system being flawed, and questionable uses of the Lore of the game. I firmly believe that the original SPECIAL rules would have little issue with a real time environment, the only thing that would have to change is APs. Bethesda choose to waste time and resources to scrap it and replace it with their own incarnation, which, no offense to Bethesda, comes across as a very weak system. I suspect this is because they really don't have much experience with actually writing a full blown RPG system.
Now, you might say "But wait! Bethesda has been making RPGs for years! How could they NOT have experience with writing RPG systems?!", to which I will say this: Their RPG systems have always been around their gameplay. So they didn't NEED to make an actual full blown RPG system. Fallout was a variation of GURPS, with changes made to it so that it was their own system and not GURPS anymore due to licensing, so SPECIAL meshed much more perfectly with the gameplay.
In the last 3 Bethesda titles I've played (Morrowind, Oblivion, and Fallout 3), they've all had glaring issues with their rules. Fallout 3's are especially noticable because we've seen how the originals WORK. But with Oblivion, it was easier to finish the game by NOT levelling up. Morrowind had the "OMG UNARMED OWNS ALL" issue that I was never really happy with (it's been many years since I've played it, so I'd need to review it again to put more details, but the unarmed was really broken in it, and made me fear horribly anyone without a weapon)
If I was in charge at Bethesda, I would be head hunting some of the bigger names in the pen and paper RPG industry, so that a better more balanced and functional ruleset can be made for their future titles. Because it's really an area that I think they are very weak in.
By the way, this is a very interesting and engaging discussion, so I hope it doesn't devolve into senseless bickering. The more discussion people have, the more enlightened and enriched their minds are