Actually it CAN be pointed.
It is pointed by manipulating the feed-point/focus-point to look at only part of the reflective parabola below.
It is true that the only time the entire reflector can be utilized is when the target is directly in front.
The farther the target gets from 90deg the lower the gain.
With a reflector that large the movement of the feed where there is gain to point off a bit must be only a few tenths of a degree, depending on frequency.