The Hero=player figure, the one who is going out in the world and doing all the quests.
Think about it, whenever you're sent into and enemy stronghold to kill X, subterfuge is the only possible way the player character could survive. Most areas are so heavily fortified, it would be illogical for any one person to get in there, slaughter everything and get out.
A warrior approaches the ogre den, the ogres ring the alarm, he'd get swarmed and smashed to bits. No armor is gonna safe you from fifteen angry ogres, lorewise. No matter your fighting skills or your prowess in the arcane arts. Most missions the questgivers send us on are suicide missions and we wouldn't survive them outside of some freaky incidents... unless we were some kind of infiltration specialist.
Get in, kill and collect discreetly, and get out with everyone none the wiser.
There are a few exceptions and of course, Dungeons and Raids. Questing, though... if you're not some sort of stealth assassin, you might as well be toast.