Final answer:
Slavers shipped enslaved individuals in horrible conditions to maximize profits, as packing more people into the ship increased the likelihood of a profitable voyage despite high mortality rates.
Step-by-step explanation:
Slavers shipped their cargoes in such horrible conditions primarily to maximize profits by reducing costs. By packing as many enslaved individuals as possible into the hold of the ship, they aimed to ensure that enough people survived the brutal voyage to still profit upon their sale in the Americas. The terrible conditions included poor ventilation, insufficient space, and extreme discomfort. The voyagers were also subjected to diseases like trachoma, which could leave victims blind and thus unsellable, further implicating the profit motive as central to the neglect of humane treatment. Cultural norms and the dehumanization of the enslaved also facilitated the justification of this mistreatment, and while there was certainly inefficiency in transportation methods, it was the relentless pursuit of profit that mainly drove the inhumane shipping practises.