I'm going to use a "Slippery Slope, look where it's going" argument, similar to the one that says that humans will be immobile in a million years, to show the problem with mmos. In about five decades, MMOs will have degraded into a style in which a character moves around a large plane with the arrow keys, gaining xp (which is useless, as nothing can be done with it) by clicking repeatedly on himself. The only social element will be the chatting (characters can't even bump into each other, they just move right through one another). In a few more years, the characters won't even be able to chat. In a few more years, the character classes will have degraded (They already were only different in appearance), all characters looking the same. In a few more years, all characters will be red circles. In just a few years after that, characters will be immobile. After that, the very multiplayer element will be removed, leaving just a red circle that raises a bar and flashes when clicked. In the following years, the flashing is removed, leaving only a circle that raises a bar when clicked. The final act is to remove the bar, leaving only a circle that can be clicked. And yet, as creativity decreases, popularity increases. At the end, all people are addicted to the click-circle, even the world government, which requires all to click on it constantly. Humanity slowly uses technology to remove necesities like food that stop from clicking as much as possible. Networks of people form hiveminds, and click on the circle together simultaneously. These merge and merge, forming only a few hundred hives. Finally, as they merge more and more, all humanities previous glory is erased, as one giant mindless supercomputer that clicks on a circle every picosecond.