Paulo Freire in Pedagogy of the Oppressed about how the Oppressed internalize the Oppressor, most of the time without admitting it.
It's not that people shouldn't engage in rhetoric based on authentic principles, but the key words here are: "engage", how? in what manner?; and "authentic"? bearing what degree of rational validity and reliability?; "principles"? precisely and rationally exactly what priorities?
Bias is inescapable if you are alive.
Some important questions are about how honest and open and inclusive everyone is in LIVING what they say concretely and organically. Recognizing to what degree each is biased or prejudiced and making personally conscious decisions about that in terms of ones own concrete life (which would be the opposite of propaganda, freeing one's self as much as possible from propaganda). Freire would say that these motives should result in a personal praxis which liberates one's self from the oppressor within and, hence, others to the extent that that is possible, so they then have a chance to free themselves too. Real freedom, thus, gets paid forward concretely at the bottom of all conventional power structures.