Ok, here's a rant for ya:
Fallout 3 just has more in common to TES4 than Fallout 2. You can't deny that. It has, some of which Gabriel pointed out already, same controls, same graphics, same core structure, same UI, same menus, same gameplay, same design goal, similiarly dumbed down mechanics, same black and white story, same dialogscreen, same map design, similiarly empty and one dimensional characters etc. The only thing that resembles Fallout is that it shares the setting (it has vaults'n stuff so it must be Fallout), but everything else stems from Oblivion. Every improvement to the game was made over what Oblivion did (or was thought doing) wrong in its iteration of the same system, not over how it was done in the original Fallouts. With that in mind, how is "Oblivion with guns" a ludicrous thing to say?
When I said "whether or not Oblivion was a good game bears no relevance here", I meant that it shouldn't matter here because this is not TES, this is not part of that series - what TES does right or wrong should, on a general level, have no bearing on how Fallout is done. They're different animals and should not crossbreed, and if they did, Fallout should be the prominent source of genes.
End of rant.
I think I have some coffee now.
What you are ranting (your word) about mainly in your post are comparisons that could be said to be of similarity between about any two games. Controls, graphics, core structure, UI, menus, design goal, mechanics, dialog screen. In other words, just game structures common to most games.
Completely ignoring how far so worlds apart the actual game-plays of TES4 and Fallout3 are. THAT is what makes the difference between the two games. THAT is why making the comparison and saying that Fallout3 is "Oblivion with guns" is so ludicrous.
When I last argued the case, it was actually claimed that there was magic in Fallout3, yeah right, that a metal bazooka rocket was interpreted as being casting magic. I didn't bother asking how much MANA was used to "cast that rocket" as it seemed that intelligence had left the forum.
Need I go on to take apart the other ludicrous inconsistencies of saying that Fallout3 is "Oblivion with guns".
Yes, Fallout3 has more in common with Fallout2 than TES4.
Immersing oneself in Fallout3 there is absolutely no feeling of being in anything other than a FALLOUT game.
I do accept though that some may have different degrees of depths-of-immersion when they play their games, with the possibility of different views,'cough'.