Funny, you're making it sound like the many who don't like NV but like F3 are idiots, I have played every Fallout game (haven't beaten Tactics or F2 yet) and I find New Vegas the worst (ofcourse I'm not counting the Burned Game).
It was dull and there was nothing dangerous or even difficult about the game, as you say "Common sense= use it."
And F3 conitnues the Enclave's story with FEV and such. The NCR played a minor role in F2 so it's not like a game all about them and new factions should be F3 instead of a game about the Brotherhood and the Enclave with supermutants playign a major role too.
The thing is, I too have played every Fallout game (I stayed the hell away from the burned game) but I find Fallout 3 to be the worst, second to PoS.
When I first played Fallout 3 I thought it was amazing and original, with everything being Bethesda's amazing writing skills and plot... Then I picked up the 'Fallout Trilogy' pack and played Fallout 1 and 2, and realized that literally every single thing they did was a recap and recycled verison of the original games.
The ONE thing they did to try and please the older fans is add in the Brotherhood of Steel, the Enclave, Mutants, and the FEV.
But you know what?
THAT MAKES NO DAMN SENSE! The FEV was only in West-Tek facilities, it was stated in the first game damn it. The Brotherhood of Steel? They literally had no point or reason in travelling east; nobody knew what in the hell was there, if anything was there at all. You don't send a full blown chapter or division of ANYTHING out across the nation blindly- it's like being in the middle ages and putting every soldier in an army into a boat and start sailing across the sea trying to find land with no idea the first thing about the world, it is suicide. People, armies, or whatever the hell it is you want to call them would only move if there was something with tactical value; which there wasn't.
The Enclave? Okay, this can be a bit more understandable, they got beaten and lost their homebase to the Chosen One and then get hunted down and slaughtered by the NCR... But they go ALL the way across the states? Really? Nobody would do that, no matter how hard the defeat... Say it was Italy, if they lost their cities, they would not run to the middle east because of it. That's how their supposed 'Tactical' retreat was, nonsense.
Super Mutants? Good god, how on earth does this make ANY sense at all? There were no more VAT area's, no more facilities, but yet somehow some were shipped to Vault 87 for an 'experiment' when they had a whole damn facility, no wait, TWO whole damned facilities to test the damn stuff... seriously, it's like Bethesda looked at the wikipedia, skimmed over the storyline and factions and said 'Oh, and this is mine, and this is mine, and this is mine!' like that one kid from A Christmas Story.
Oh, believe me, I have a whole damn lot more to say about Bethesda's 'original' storyline.