One fact of life for complex software is that there are so many permutations of play and of gaming rigs that it's impossible to test everything much less fix everything. To produce a game that is flaw free you need two things: infinite time and infinite money. Even if "Bethesda" as a collective doesn't want the game to go out, the marketing folks and the accounting folks of Bethesda DO want it out, and the company has to generate cash flow or go under.
That said, there are minimum standards of testing that should be exceeded, not just met. And that said, FNV doesn't seem buggier than Morrowind or Oblivion or FO3, we're just dealing with these bugs NOW and the process of both patching and modding fixes is relatively young. The same bugginess seems to apply to Civlization and Total War and Age of Fillintheblank, and according to forums each in turn is the buggiest game ever. They all crash, and I've long since learned "save early, save often...after I get burned AGAIN." [By the way, the buggiest game of any of these series was Daggerfall. I still have scars.]