The key sentence here is "to change PAX waypoints".
Waypoint rotation is not used for Passengers Waypoints, because they are just...waypoints, passengers will just walk from one to the other, and their orientation will be controlled by the heading of one waypoint to the next, so waypoint rotation is not active when editing Pax (and Airport Walkers) waypoints, because it has no meaning.
The only case where the rotation of the waypoint *itself* has a (very important) meaning, are the waypoints used in the Custom Pushback editor, because they are not really "waypoints", but control points to fit a spline curve that would be affected by the rotation of the control point.