Basicaly, what your eyes see is techicaly 2D too, if you think about it. It becomes 3D because you have 2 eyes, and the brain reads the offset between each version of each eye, giving you an instant measure of 3D, but it's just basicaly 2D twice.
If you close 1 eye, you lose a lot of 3D sensation, but you stil got a little left, because your eye has to focus, and whatever is out of focus is blurry, but it's still 2D, you motherfuckers.
What the eyes are seeing is 2D yes, but for fuck sake itís classed as 3D or CG animation, due to the methods of creation, and to differentiate between hand-drawn and stop-motion(Which some people also call 3d animation)
If you think this is classed as 2D animation what the hell are hand-drawn and stop motion? Hell, Id love to know.