Well....
You obviously are new to Beths games, aren't you? In fact, as other have stated above, the game is remarkably stable, in an environment that becomes more complicated every month.
Consider this - as Oblivion came out nobody could play this game on a notebook, there were no Intel graphic chips, everybody played on PC, the only difference being the type of graphic card one used. Today you have notebooks which are misconfigurated, so that games does not know which graphic chip to use, there are huge numbers of different graphic cards, SLI, different memory sizes and configurations, and last but not least 3 different and active versions of Windows (Win 7, Win 8.1, Win 10).
For this environment the game is not bad. I have to admit, I have a fairly strong and stable PC (Win 7 Ultimate, 16GB, GTX980Ti), and the game runs very stable for me. With more exotic and rare configurations there can be problems.
Also - many of the problems are all well known, and probably are coming from the engine used. That some quests will have glitches is very hard to avoid, with the complexity of quest lines. The quests alone, with all the variants a player can and will use are a testing nightmare. But this could be tested still - only there are subsystems in the game, which are not very dependable, probably a side effect of the engine used. Pathfinding is not very dependable, sometimes NPCs tend to hang. The new dialog system allows not only the player to abort a dialog midways, it also allows sometimes NPCs to walk away mid dialog, which also aborts the dialog. Since dialogs control quest variables, a quest can be left hanging in an unstable or undefined way. Spawning also sometimes does not work correctly, proved by cows or entire trading caravans on a roof...
I cannot really understand why they do never address the underlying system problems, but maybe this is not possible with this engine. But with the tools they have they have delivered again a very creative work. Their PR was never really good since Morrowind. Oblivion was really bad, overhyped and with countless small bugs and a really unimaginative world, where they relied too much on automatic methods and a dumb and lazy sort of level scaling. (Remember OOO, Oscuros Oblivion Overhaul, it became playable with this huge mod)
But they showed that they can do better again with FO3, which is, despite all criticism a very good game. The same goes for FO4.
But their PR could be better. Other companies show, that it can be done better. That they refuse to communicate and just every month drop a bone to the press now - if even that - is a bit .. poor. I wonder why they get away with it.