Amnesia is, in my opinion, the best horror game I've ever played. But to fully understand how brilliant this game is, immersion is very important. A dark room, headphones and high volume are a must. The OP proves that he didn't fully immerse himself because he was
trying to explore the boundaries of this game.
Yes, you can jump on every object, throw objects at monsters or try to make use of every little glitch this game has. Because this is a game and every game has bugs.
And yes, the monsters can't jump or fly or hit you when you're standing on an object. Does that make them any less scary? Not if you fully immerse yourself.
If you immerse yourself and believe that
you are Daniel, would you EVER deliberately lure a monster to your position and jump on a tiny box? No.
Evertime I enter a room in this game, I block the door with objects. Even when I'm 100% sure that there are no monsters nearby (for example, in the beginning of this game). When I see a monster, I run away and hide in a dark corner.
AI, graphics... all those things don't matter as long as they don't break the immersion. In Amnesia, they don't. I think the AI and graphics in Amnesia are great, especially if you consider that Amnesia was made by only five people.
To the OP: play the game again like it's meant to be played and then think about the AI again. I'm sure your opinion will change
.