To the extent that they siphon dollars and energy off from more productive ways of doing things, that’s unproductive. Suppose instead of getting volunteers to read to children, they got the volunteers to work a few hours for Mom at McDonald’s or cleaning houses so SHE can read to the child and improve the mother-child bond, which we often complain is weak among single working mothers. Much better, and encourages skills the mother can use at other times when the volunteers are off, leading their own lives.