The only thing they share is the RGB camera and that is not really used for gameplay with Kinect, just to snap photos and shoot video mostly.
So get annoyed all you want but at least learn what you're talking about first or else you're just getting upset for no reason.
1. It does know where the person once, it can map your body (saw it in a move tech demo, but it was the eye alone doing the mapping http://www.youtube.com/watch?v=hoeea0x4LxM time code 5:09) it has trouble with depth without the move yes but you can use algorithms to guess how far based on size to make up for it
2. You are right on the identification but that has nothing to do with 3D camera it's software MS recently patented (2D laptop cams can do it with the software, if the software was used on pseye I see no reason it wouldn't work)
3. As for seeing you in 3D the only point you are right on what but again it can guess how far away you and and what exactly are the advantages of that gaming wise? There are almost no games where you move yourself on a 3D plane, kinect joy ride being the exception, of course that one is semi on rails the amount the game automatically guides you and you really only move from side to side I don't see how pseye couldn't do it, it would just need more obvious movements but thats about it the game isn't impossible you just have to change how it controls which really wouldn't be the hard
You are the one that doesn't know what they are talking about not me