There are sayings, often referred to as Chinese curses, which appear to be blessings on first sight, but on closer inspection are in fact a curse on the recipient. I believe that for games such a Chinese curse would be "may you win every game you play!". Because, with the obvious exception of gambling where there is a financial gain to be had from winning, the interest in playing games is the excitement to find out whether you can win. If the win is assured, the interest in playing disappears.
Unfortunately video games evolved in part from arcade games, which had a "win to progress, lose and you need to put in another quarter" business model. Our PC and console games don't need quarters any more, but the "win to progress" design stayed with us. Games still frequently use a design in which you *need* to win to get to the next part of the content. If you lose, you are punished by having to play the same content again, over and over, until you beat it.
It appears that this instilled into gamers an absolute horror of losing. They believe that if they play and lose, they can't have fun. Warsyde, The Babbling Gamer, tells the story of a friend who doesn't want to play World of Tank any more, because he can't win all the time in that game. But if you want to always win, you can only play PvE games, and then you still have to either use god mode cheats, or play games with a difficulty level so low that it is practically impossible to lose.
The sad thing is that this is purely psychological. In World of Tanks you do not need to win to progress. The developers realized, rightly, that while it is impossible for everybody to win in a PvP game, it is perfectly possible for everybody to progress. You just need to remove the arcade game artefacts from game design, and have people progress even if they lose. Less fast, with less titles, medals, and achievements, but letting them progress anyway.
I do think that there is a lesson to be learned here for good game design, which is not only applicable to PvP games. Instead of tuning a MMORPG like World of Warcraft or a single-player game to such a low difficulty that there is simply no challenge any more, just to avoid anybody getting stuck, you can simply make sure that progress is always possible. For example L.A. Noire allows players to skip sequences they get stuck on. I'd rather have such legalized cheating in games than game companies realizing that very few players ever finish single-player games any more and deciding that games are too big and too hard.
MMORPGs are even further away from what players actually want than most single-player games. They developed a "single difficulty fits all" game design philosophy, in which even the exceptions to that rule, like "normal" and "heroic" dungeons, end up not being alternative choices. Some content exists only at extremely easy difficulty, other content only exists only in one or two flavours of "very hard". Thus players find themselves in situations where they either always win or always lose. A curse indeed, because neither is much fun. It would be much better to encourage players all the time to tackle the hardest possible content they can handle, while always giving them the option to tone things down a notch or two if they are in danger of getting stuck.