To be honest, I don't really see how "being closer to the originals" is a virtue, I don't subscribe to the 'original is always better' school of criticism. Bethesda know how to make great role playing games, and it's down to them that Fallout is now experiencing this renaissance.
Anyhow, my points are being largely overlooked in favour of the above abstractions, and (in my view) undue praise for a complicated but ultimately clumsy and poorly converyed story, so I will just reiterate as concisely as I can. Fallout 3 had a more involving story, an eminently better convieved setting, much more detail, the element of chance and chaos that always kept the player on edge (unlike the cloned experience of replaying New Vegas) and is generally done with more style and aesthetic flair - which is important.
I hope Bethesda keep Obsidian away from the franchise in future. It's not like this is the first franchise that's been put on the backstep by Obsidian - need I invoke the utter folly that was Neverwinter Nights 2?
What's happened is that Bethesda probably wanted to make an earner off the back of Fallout 3, which is no bad thing, but being preoccupied with a much more valuable project (TES V) delegated the task to a company not nearly as capable as they are.