We argue that the long neck of the sauropods may have been under positive selection for low foraging (instead of, or as well as, exploitation of high foraging), if this long neck allowed a greater area of food to be exploited from a given position and thus reduced the energetically expensive movement of the whole animal.
Yeah, if.Without studies of neck mobility beyond the current controversy, and studies of locomotion cost beyond Paul's back-of-the-envelope calculation which suggests this cost was very low indeed, and studies of the cost of holding the neck horizontally and of raising it (assuming the bones allowed both, see above), this conclusion sort of hangs in the air.