I've been browsing a thread at story-games.com, and a college game of D&D 3.0 comes to mind.
I was playing a thief in a very brief (maybe 3 sessions?) adventure, and I think it was around the time I was checking the hallway for traps every five feet when I decided I was done with conventional Credibility.
In that story-games.com thread, they're talking about sharing information. But really, now, there IS no information, only what the GM is deciding from moment to moment! He might have taken notes and made preparations beforehand, but that's like saying a speech is set in stone (and cannot be changed, no way) just because you brought index cards.
It's a game - the contents are imaginary. If you like being surprised by hearing other people's ideas, with timing and pacing and whatnot, that's cool. That's totally cool. But sometimes I think trad gamers can get a little caught up in "what's really happening" and forget that, hey, we're all making this up as we go.
Honestly, the fixation stems from the amount of prep the GM (or whomever) puts in - you don't want to "break" or "interrupt" the thing being devised for your entertainment, so you sit and let it unfold. But it's a whole lot easier for everybody in the game (less work for the GM, more entertaining for the players, IMO) if credibility is shared.
All you need to do to change credibility is to give players the power to create plausible play elements. Conflict resolution is all you need: give players the real chance to decide what happens in the story, and their creative energy will explode! forth, saving all us Game Masters a ton of work. Setting stakes is where it's at.
As for the important, if redundant, issue brought up in the thread, that of respecting people's right to play as they please, absolutely! That's fine. All I ask is this - if you notice a frustration or discontentment with your RPing experiences, consider giving it a try.