They are supporting the advance of scientific and pharmaceutical drug development to protect us against potential health threats, whether from bacterial infections or viral sources like influenza.
In fact, one might argue that the pharmaceutical industry is obligated to run such expensive trials to help advance the understanding of medical outcomes with new medicines.
Whatever the benefits, there's no getting away from the fact that human embryonic material has become a research tool for the pharmaceutical industry - that the moral status of the embryo has been lowered for the sake of medical advance, profits, and extending the lives of an increasingly elderly rich western population.