I'm sure this is going to sound quite snarky, but it's because the games are, well, "finished."
The amount of backlash from Skyrim was much more vocal, IMHO, than NV or FO3's backlash was from the initial launch. Due to that, and due to the fact that the NV and FO3 issues truly rear their heads when you add the DLC, by the time that people playing the PS3 saw the problem with the fallouts, nobody was working on developing the game anymore.
So, from an honest to god business perspective, why would Obsidian or Bethesda try to patch and fix games they already sold and aren't trying to push content for? Skyrim still has DLC waiting in the wings, fans throwing a fit about the problem a few days in, and the gaming press (lol) asking questions. That's not good for the 10 to 15 dollar digital crap they need to push to you in the future. If your game doesn't work, you won't buy their shit. Now that you can play past a hundred hours though, hows another twenty for cool ten dollars? Eh? Huh? It only took us three months! You should be grateful!!
My only, and truly pointless hope, is that people who purchase the FONV: GOTY edition have a terrible experience, throw a fit, and possibly that game gets fixed. Honestly though, not likely.