The challenge is the thing

From Through Dungeons Deep, page 5:

"A fantasy game isn't played so that a single character wins. No one is trying to beat the others. The idea is to have a good time facing challenges and, hopefully, overcoming them -- all as a group effort. Everyone works together."

Ah, how that last sentence has fallen out in some games. I've seen it happen. I like it better when the group all does work together, but I also know I can't count on it.

from page 15, immediately following an example of play:

"This example showed several things. One is that the player characters never once made a decision based on game rules; their actions were based on the situation described to them, their knowledge of their comrades and common sense. This is what makes role-playing games feel so realistic."

Indeed. I couldn't have said it better myself.