Mastery in MMOG´s

So a while ago I had an interesting discussion with a teacher where he said that what makes Massive Multiplayer Online Games (MMOG´s) so hard to design is that there are a big amount of players, that all are different.
His point being that they started playing at different times, they play via different time schedules (some play 6 hours a day, while some play 2), some are quick learners, some are not.
Now the biggest challenge in this is the people […]