Players are often lazy. While they enjoy playing games, they might not share Game Master's enthusiasm to the campaign setting and it's world, and as getting to know it could require reading somewhere from 10 to 150 pages, they might not really know or understand many things that come up during the game.
Therefore, a quick start sheet that gives you all the vital information of the world in perhaps 1-3 pages should be made for EVERY campaign setting. Except perhaps those where players are expected to know everything (some real-world based games) or they aren't supposed to know anything about (Paranoia!)
I've accepted a challenge suggested by an author of a campaign setting to create a quick start sheet for the setting - I'll publish it soon, until that I won't reveal it, but those that have been following my posts or discussions at Savage Worlds forums probably guess what setting I'm talking about!