NOTE: Exaggeration and over-simplification are used intentionally below to clarify a point, not to be contentious. Please consider this before flaming.
Seems to me that what we're really seeing here is the disconnect between two personality types and their default world views. On the one hand, we have people like chemist (and me, and maybe at_nyc), who are inclined to be auto-didacts. We tend to trust things in print more than things that are spoken, and feel the need to do our own independent and deliberative research ahead of time, before going into a new situation. We like to mull stuff over before talking about it with anyone or encountering it in person. We abstract things, and then enjoy correlating the abstraction to the real and finding the correspondences and gaps. (Some call this "debugging.") A map is a highly useful abstraction, after all. We'd prefer to get other people's input in distilled, well-vetted form, representing the synthesis of contributions from multiple authors. Having to interact with people socially and in real time for the purpose of collecting "information," knowing that much of it is likely to turn out to be chaff, is anathema to us. Finally and most importantly, we just like maps and will study them for hours for the simple pleasure of it. When we start thinking about going to a new place, the very first thing we do - before telling our friends or looking up the best restaurants or pricing plane tickets - is go get some maps. Because we're invested in maps, because we believe in maps, it matters a lot to us when they fall short.
On the other hand, we have people who focus more on the concrete and the immediate. These folks just show up for the adventure and experience it as it happens, relying heavily on their network of friends to help understand and react to things on a just-in-time and only-as-needed basis. If they're on the front side, they may not know or care what the back side looks like at that moment. They value what trusted people tell them in person and face-to-face much more than they value what they read. To the extent that they think hard about the day's skiing ahead of time, they may be anticipating interpersonal events more than they are anticipating seeing what such-and-such a canyon looks like or how steep that famous bump run really is, let alone whether it lines up with what the map told them to expect. These are people for whom maps may play only a very small role in their experience of the world, and therefore they don't care deeply how complete or accurate they are.
Now obviously we ALL operate in BOTH of these modes all the time, and in every blend of them in between. I am a map person, but am very much aware of maps' limitations. I benefitted hugely from the guiding donated by Bears at the Gathering last month, not to mention being grateful for the good cheer and camaraderie they brought along. I wouldn't have had anywhere close to the quality of experience I had without that first-hand in-person help. And even the most people-centric skier sometimes finds himself alone with a map and really needs it to be correct so he can get back to the correct parking lot or whatever.