Some day we may be able to produce an alternative product that either replaces blood in injury and cancer victims or helps their bodies produce the extra blood they need very quickly. Which may take the issue of injecting other human's blood into such patients and also eliminate the need for blood donations. But, such technology is likely still a century away, though it is getting closer. Though there is no real reason for not allowing blood transfusions.
The religious reasons cited by an entirely brain dead religious organization is extreme nonsense.
Why would this even be a debate? Blood transfusions have saved so many lives. What if they weren't allowed and there was a horrible accident and the only way to save someone was to give them a blood transfusion. Transfusions have saved my grandparents and many other people. Again, why would this even be a debate?