I think that there must be something more going on memetically than just an aversion to relationships with power imbalances. Only the most conservative individuals seem to object to the idea of a wealthy middle aged CEO watching legally produced pornography featuring eighteen year old actresses, but most individuals seem to have an aversion to anyone who watches pornography which simply simulates children in sexual situations through animation or computer graphics (I haven't read any opinion surveys on this, but there is an OkCupid question asking whether it should be illegal to look at animated or otherwise artificial porn of children, assuming it can be absolutely proven that no real children were harmed; most people regardless of political affiliation answer yes.)