A post by Raymond Daley on his experiences reading GCA prompted me to a realization which I'd sort of had, but which hadn't fully gelled until now. Namely, that there is another phenomenon which determines reading enjoyment (at least of adventure-focused fiction, which a lot of SF/F is) in addition to WSOD (Willing Suspension of Disbelief): Suspension of Tension, or the willingness to accept that the characters are in peril. The two are of course related, but they are not identical and it is quite possible to have one fail with the other intact.
I write my stories from the basic proposition that, in the long run, good triumphs, evil fails. This carries with it the very strong implication that the heroes can't die, or at least will very rarely do so, and if they DO die it will be towards the end of their adventures and in a sequence of tremendous import. For Mr. Daley -- and I have no doubt many others -- this weakens the tension, perhaps to the point that there is no suspense left, no Suspension of Tension remains, and thus they have no connection with the events in the novel because, to them, the entire sequence of events holds no emotional weight any more.
For me, this isn't a problem. I can watch, for example, an episode of the Six Million Dollar Man, knowing not only that the hero's going to survive, but even remembering HOW he gets out of his predicament, and still feel the tension. But this is very similar to the WSOD -- Willing Suspension of Disbelief -- in that the reader or viewer must accept some postulate. In the case of WSOD, you have to accept that what you're viewing is a world of some sort and that the story you're following makes sense within that world. For some people, the WSOD is almost unbreakable if the label "SF" or "Fantasy" is applied; anything, no matter how ridiculous, is explained by the fact that it's "science fiction" or "fantasy". For others, the world has to be self-consistent. For still others, it has to make sense in even more restrictive ways.
Similarly for Suspension of Tension: the viewer has to accept that there is a risk or danger for the character. For some people -- such as myself -- the important thing is whether the CHARACTER believes they are in danger, and we only ask that the solutions for their problems not be pulled entirely out of left field, but at least allow me to look back and say "oh, THAT was what that meant". For others, it requires that they believe honestly that the characters might die at any moment -- that no character is sacred -- or they can't invest it with any tension.
For the latter group, nothing I write is likely to work, at least if they realize that I'm writing positive-slanted adventure fiction. That will signal to them that the main characters are almost certainly going to come through,and break the Suspension of Tension.
Just a little observation I found interesting today.