This I agree with, but it's more for the gut response of "I don't trust people to determine other people's values." I wonder if the latter could be handled objectively, but I'm not sure I'd trust humans to do it.

We already have to deal with this when we raise children. Western societies generally favor granting individuals great leeway in modifying their preferences and shaping the preferences of their children. We also place much less value on the children's immediate preferences. But even this freedom is not absolute.