Better that than one further elephant or rhino is killed for its tusks, horn or feet. Like deep-sea fishermen, soldiers, and other criminals, they know the risks and presumably accept them. If they cannot foresee their risk, better for the future of humanity they be eliminated from the gene pool.
Yes, the well-being of all non-human life, especially the big cats and other large and impressive mammals, in some sense falls within our responsibility. Like everything else worthwhile that is being gradually destroyed in the name of profit and progress, (architecture, wildlife, traditional skills and values, the natural landscape, the environment in general) it is probably something worth preserving for posterity.