NFL end zone pylon placement
 

In watching the AFC Divisional Playoff game between the Chargers and Colts I noticed that the pylons were placed out of bounds. What is the point of this?

In a close play at the goal line, wouldn't it be better if the pylon represented space within the end zone and in bounds? The way it is, a player could reach the ball into the pylon before being down or out of bounds by body contact and it would prove that part of the ball was out of bounds after crossing the goal line plane but would provide no proof that any part of the ball crossed the plane in bounds thusly signifying a touchdown.

By the way, looking for the NFL rules online regarding the proper placement of pylons produced no results.

Official NFL Playing Rules-Field Markings (5) The four intersections of goal lines and sidelines must be marked at inside corners of the end zone and the goal line by pylons. Pylons must be placed at inside edges of white lines and shoul not touch the surface of the actual playing field itself.

They're all placed OB
 

NFHS-

1-2-Art. 4... A soft, flexible pylon, which is 4 inches square, 18 inches high, either orange, red or yellow in color, and does not constitute a safety hazard, shall be placed at the inside corner of each of the intersections of the sidelines with the goal lines and the end lines, as well as with each intersection of the inbounds lines extended and shall be placed either 3 feet beyond the end lines or on the end lines. When properly placed, the goal line pylon is out of bounds at the intersection of the sideline and the goal line extended.

NCAA-
1-2
ARTICLE 6. Soft, flexible four-sided pylons 4 inches by 4 inches with an
overall height of 18 inches, which may include a 2-inch space between
the bottom of the pylon and the ground, are required. They shall be red or
orange in color and placed at the inside corners of the eight intersections
of the sidelines with the goal lines and end lines. The pylons marking the
intersections of the end lines and inbounds lines extended shall be placed
three feet off the end lines.