sauropod necks

[StephanPickering@cs.com]

     Shalom, and new year's greetings. In Walking with Dinosaurs, and other sources throughout the years, it has been inferred the sauropods attained their long necks as an adaptation from "pro"-sauropods, the elongation of the neck allowing accessibility to foliage, etc. With new evidence that most sauropods did not reach high up into trees due to vertebral constraints, one is presumably left with hypotheses. Or are we? The zoological field work in Namibia of Lue Scheepers and Robert Simmons reveals interesting observations. During dry seasons, Giraffa camelopardalis feeds on very low Grewia foliage, and, during rainy seasons, they almost exclusively eat Acacia tortillis trees (their 18 inch prehensile tongues able to hold onto chicks in nests, ants, and the leaves). Females spend about 12 hours a day with their necks h!
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izontal (males rarely have their necks in this position, and, from a distance, one is comfortable in sexing herd members). In fact, both sexes, while feeding, have their necks bent, and are able, thus,  to eat larger quantities. As Simmons/Scheepers further observe, "long necks did not evolve specifically for feeding at higher levels". Indeed, male giraffe have thickened skulls, and club rivals (in world zoo prisons, deaths have transpired among fighting male giraffe, due to puncture wounds in the necks). Simmons/ Scheepers further postulate giraffe long necks have always been present with this taxon, and female long necks "arose as neutral by-products of genetic correlation between the sexes" (e.g., male humans have teats, but have male humans nursed?).
     Thus, could it be possible sauropods used long necks for intrasexual competition, and this a possible explanation for their presence? If camarasaurs et al. kept their necks horizontal, sweeping back-and-forth (when possible) to eat foliage, why, then, did they have the long necks?