I don’t know a lot about how the donation system works, but I think it’s a bit of a red herring to accuse her system of not treating as many people as possible as efficiently as possible, since, as I understand it, that wasn’t her objective.
From what I know about her (a little, mostly from Muggeridge’s book) what she wanted to do was to treat people as individuals, one by one, and with love. I think she went to the poorest of the poor in India because of the Christian directive found in Mat. 25 31-46, to clothe the naked, feed the hungry, and comfort the lonely, because to do it for anyone is to do it for Christ.
It seems to me that she would consider her life well spent if she managed that for even one person. I suppose the argument would then be- is it ever justifiable to use a person-by-person, inefficient method, when one has the resources to set up huge poverty-eradication systems.