Or does it? My fondest memories in any MMO almost always revolve around moments of temporary insanity -- times when we bit off way more than we could chew and somebody (or everybody) died spectacularly as a result. Heck, there's even a guild based on the premise! Still, you won't get very far exploring the range of what your character can do if you never push the envelope. Some players relish the challenge of seeing how far they get soloing a raid instance; others quail from the inevitable string of deaths. An overly cautious approach can push activities like PvP completely off the table for players who are afraid that death equals failure in their eyes and the rest of the players around them.
Does death during the normal course of questing, grouping, or running a raid you're fairly familiar with represent a personal failure to you? Do you feel embarrassment when you die in front of other players? Do you prefer that the game be balanced so that you rarely if ever die? Maybe you believe a little death and danger add spice to in-game life. If you wish WoW's overall challenge rating were a little less forgiving, do you think you'd feel comfortable with dying more frequently, or do you think the bar and community attitudes on death and skill are already firmly entrenched?