The answer we have generally come to is based on a psudo kantian interpretation of causality. One innocent can die due to inaction, but you can't actively kill one to save many.
We don't allow nonconsentual body snachers to harvest one person to save many. Alternatively we may allocate finite funds to save several lives instead of a single life. We may also choose not to spend the money to save a life
Note well: I'm not actually a consequentialist. I'm just pointing out what "for success" actually means, at least some of the time.