Why can't the Loader window be positioned on the inside edge of a dual display layout?

Due to technical limitations, if you have two displays side by side, the Loader window can only be positioned on the far left (left side of display 1) or the far right (right side of display 2). If it was positioned on an inside edge (right side of display 1 or left side of display 2) then when the window slides back it would be appear in the other display.