I once read an editorial about the hardcore gaming scene that discussed how players could stand just about any form of loss as long as it was fair and the reason could be pointed to in an understandable way. Being perpetually stuck at a specific point in a game because the boss is too hard or a level is too difficult is frustrating, it can even cause you to quit, but at the end of the day you know that it was your own abilities that stopped your progress. On the other side of this idea, you have games that cannot be completed due to hard stops out of bugs or incomplete content. S.T.A.L.K.E.R: Shadows of Chernobyl is a game that can come to a hard stop when you reach the final area (the Chernobyl power plant) only to realize that you not only will not survive the radiation without the highest level suit, but the game does not allow you to go back at this point and get it. If you don’t have a save file from before entering Chernobyl, you are SOL.
But even that isn’t as infuriating as not being able to progress due to a bug, and when it comes to MMOs, I can think of no other game in recent memory than Defiance that I have wound up quitting temporarily due to bugs preventing progress. I still have not completed the levels in Defiance’s Castithan DLC pack, released back in August, because it is impossible. If you haven’t played through the content, the missions involve a series of arenas where you rack up points over several waves of enemies. There are five waves per level, and at any time the game can suffer a fatal bug where the round begins but the timer disappears and so does your score, forcing you to quit or be killed and try again.
And then you try again only to have the system break again, so you can try again to have the system break again, in an almost never ending loop. Only by sheer luck did I manage to get through the first four arenas after multiple forced reboots over the course of the past two and a half months, and finally after having to restart the last arena three times, I managed to get through all of the rounds without anything breaking. I did ultimately complete the Castithan content pack, but had I not already purchased the season pass, I likely wouldn’t purchase any further DLC. The fact that such bugs are going unfixed after two months time is unacceptable, especially in a game that is working double time just to retain its players, as Defiance is.
Otherwise I have no opinion on the matter.