I'm going to go out on a limb and say minstrel shows were disgusting and mean-spirited enough that the historical context that contained them was overpowered by

I'm going to go out on a limb and say minstrel shows were disgusting and mean-spirited enough that the historical context that contained them was overpowered by its own characterizing foulness. Would be a pretty stomach churning thing to see today even without knowledge of the history. Definitely a coherent metaphor, in the same way 'grammar nazi' is -- conflating style but not magnitude.