[Mike O]

Why do think Homer recommended the above procedure to Swingers over the Plane Line rotation method?

This all comes under 7-2 and drawing or fading the ball.
If your a manipulated swinger- that is If you come into impact with the left wrist vertical to the ground (and flat and level), That is IF you control the clubface directly through controlling the alignment of the left wrist at impact- by making sure it is FLV, then that's what you're setting up at impact fix- regardless of ball location.

If you are a TRUE swinger - then you're letting centrifugal force line up the clubface- Then you don't retake your grip with different ball locations- you keep the same grip while changing ball location-that's when you would use Plane Line Rotation method. Because if you move the ball back- it's further from low point, and the face will be more open- or put another way - as you move the ball back- and then move the hands and club back- the face opens more. Since it is further from low point you'll fade the ball- so you rotate everything to the left - keeping the club and arms in the same relation to the body- until you've got the club face aimed at the proper starting point to allow for the fade to drift back to your ultimate target.