Im the opposite, I enjoyed Bethesda's Fallout 3 a lot more then Obsidian's Fallout NV.
Lemme guess: you liked FO3's setting more than NV's. That's pretty much the only argument people can come up with because NV is superior in almost every regard.
Is it sad that I kind of want Obsidian to shut down so the devs can go to Bethesda and handle all the writing and quest design? I love the big, open and incredibly detailed worlds that Bethesda creates but their writing is so, so bad.