Let me preface this by saying I love Fallout 1 and 2. I've been playing them since my Freshman year of high school, and have run through both of those games many, many times.
With that said, Fallout 3 is sometimes buggy, occasionally maddening, and a hell of a lot of fun. Yes, it's Fallout. It's arguably a better Fallout. Why's that? Because it upgraded with the times. For as much as I love the first two games, and for as fun as they, they really aren't GOOD games. They're buggy to the point of being unplayable (like my first run through Fallout 2), they're easily cheated (like the Glow Glitch in Fallout 1 to max stats), the dialog isn't magically better (God, far from it, especially with all the "witty" things like Cheesy Poofs and talking Death Claws and Mike Tyson references in Fallout 2) and the choices you're given suddenly "trickier" or whatever you're looking for. It's still quite easy, out of the dialog tree, to know what will happen given what you pick.
Bethesda did a smart thing by moving the location to DC, because you're no longer confined to Black Isle's version of Fallout. It's the same game world, with enough similarities to say, "Sure, I recognize this stuff", while still allowing for different things. This backlash from the old guard seems to be, really, a fight between new and old, between change and sameness.
I hate change as much as the next person, but in this instance I think it worked out for the best.