There is an obvious difference between exploitative hierarchies and the other ones.
Slavery is a good word since there is no mistaking the nature of the relationship.
Slavery is what it is, it cannot be mistaken for something else once you look at it with open eyes. We can see it for what it is though. The only ones that will whinge about emotionally laden uses of the word are those politically correct puppets of Mother Culture. For our own sakes we should insist on calling things what they are and not worrying about other's interpretations of what we are saying. I'm thick-skinned and can take constructive criticism.