I get your point, but I can't consider "enslaved" a passive word. "Enslaved" implies that you are subject to someone else's beck and call involuntarily. It describes your condition. Enslaved doesn't usually exist by itself; one has to follow it with "person" or "people," thus reminding listeners and readers that there is a human whose condition has been suppressed.

"Slave" on the other hand, is an object or tool; it is not a person. We have been accustomed to using the word "slave" for centuries, and only in the past several years have we employed a term, the meaning of which, actively includes a human being. "Slave" also omits the function and responsibility of the enslaver. We must remind others that "slavery" was not a neutral condition. It required the "over" and "under" whose contrast you prefer, and everyone was aware of which was which. Being an object and not a person is beyond passivity. Let's examine every word.