I recently ran across some photos from the National Guard Marksmanship Training Center and… I have no idea why these soldiers have chosen to mount a red dot at the very end of the rail.
It goes to show that even soldiers can be uneducated in the proper use and implementation of their own standardized equipment.
The problem with mounting a red dot further away from the eye is that you greatly decrease the FOV through the optic. Doing so gives the dot less room to move in the optic window before it disappears as it nears the edge. Bringing the red dot closer to the eye gives you more room for the dot to shift inside the field of view and this makes shooting from un-conventional positions easier. If the two guardsmen here attempted to shoot under a barrier or had to position themselves and their rifle in a less than optimal position… they may not be able to acquire the dot.
Bad, and sometimes strange, habits pop up in all manner of places. Keep an eye out for wonkiness and learn the inns and outs of your equipment and its best use on your rifle.