I run dedicated original settings, some of which have been around for awhile. I like role-playing in these with my players (and new players) so as a GM I have to make sure they don't have to read an encylopedia. If I wanted to run my medieval fantasy I would have to explain the setting, some terminology, the timeline, the races, and how magic works. I'm not going to explain it in one sentence, but I'm not going to force a prospective new player to have to read six paragraphs of the history of magic and it's laws and the organizations in them. A good role-play lets players know what they are getting into and explain it so they aren't lost in the dark.

Also, that above summary you just posted was absolutely terrible and not because it was a summary.