I actually took my GameCube over to a friend's house tonight. She thought the game sucked. Mainly because she sucked at the game I think, but her main complaint was that the camera angles sucked, and she couldn't point and click at the enemies to make them die.
I gave her my standard lecture on how PC Gamers just suck at any game where you can't click on the enemy to make them die, but she just said that she didn't think that when backtracking she should have to put up with a camera angle that showed 10 feet in front of her. I told her that no camera system was perfect, and refrained from telling her that she was on crack.
In short, the answer to your question is that Eternal Darkness is intended for a person who has a love for dark things, and has a minimum of ability to solve simple tasks of dexterity and problem solving. My friend had a problem differentiating the R button from the A button.
Eternal Darkness is a very intellectual game, and the true genius of it may very well be over some people's heads, given the truly literary atmosphere of the game. If you don't like to read, and you don't like deep things, it's entirely possible you don't like Eternal Darkness.