There is nothing controversial about that at all
Several people took time to express their disagreement at several times, which shows that the statement is strongly controverted.
it is a true fact that all 2-D images are distorted, since they are all missing the third dimension which consists of everything along the Z axis.
It is true that 2D does not have a third dimension, but if there is no depth in the first place, the 2D representation is not distorted.
A text on a paper for example does not change if you read it with one or two eyes (there is obviously inherently no third dimension); and there are many other examples.
In a lot of games especially, the notion of depth does not exist.
To come back to the Nintendo 3DS, I played only one game on it and the stereoscopy was useful (in the gameplay) only once or two when the camera was fixed, purposely set to remove any monocular depth cue. The situations when it is true are not that common, and thus stereoscopy does not add much in the games: monoscopic projection is generally enough to have the joy to play, without the inconvenience of the narrow sweet spot.
stereoscopy is a distorted view of the true three dimensional world
I agree. By the way, the distortions are opportunities for artistic expression.