For the most part, the GM is not present is just a series of methods the players use. Rotation of ST duties is most typical, because most players are NOT comfortable with the idea that they are making up everything as they go.
Basically, only extreme fans of a given genre or property, who are happy that it played out "right" can easily be without a GM. You see that in folks who play MegaMan or Video Game or Cartoon based properties. They love how the property was portrayed and they want to create more of that. They don't need mystery, or even uncertainty in conflict. Cobra, the Decepticons, the villains are (almost) always defeated, and when they aren't its a conscious choice, not a wargame method of deciding.
I have looked at ways of having a set truth that is unknown, like Clue, where the Who, Where and How are in fact set and known by no one. However, you can only produce negatives with that set up, you can't easily generate information to discover that reacts to the true information in a rational and distinct way. The Castle of Magic boardgame used a list of like 16 numbers on each card so people could find out SOMETHING about hidden truths, but its still very factual stuff, not characterized. Examples: Person A is NOT from Faction 1. Faction 2 is neutral towards Goal Beta.
In the end, (I think) players would like characterization and interactivity with the unknown. That always, even if briefly, scene by scene, topic by topic, requires someone to know the truth and be the ST/GM for a bit.