Even as a teenager back in the '70s when the policy was uber strict (aka no blood at all), I could not reconcile with myself that a symbol of life was more important than life itself.
One should do everything possible within their power to save a life, including the provision of blood.
Their policy was also in contradiction to the belief held that if given the chance, anyone could be a Jehovah's Witness. Not true for hemophiliacs and others requiring whole blood products to survive.