If a person wants a song to promote justice or protest injustice, then that song had better be accurate. Why? because we are inundated by songs, movies, news and propaganda intended to manipulate our emotions. In self-defense we block it out, starting with what seems least likely to be true.
When I see that basic facts are wrong in a work, I decide the entire work is not worth my attention.
An example is the ballad "The Four Maries" I used to feel bad whenever I heard about the lady in Queen Mary's court who killed her baby. Now I know that there is no record of anything like ever happening, and that the song is a cunning piece of anti-Catholic propaganda. It's got a pretty tune, but now I say the hell with it.