In some ways, I think you can actually feel much more for Madame du Barry than for Madame de Pompadour. Pompadour, for all she is, as Dr. Who says “uncrowned Queen of France, actress, artist, musician, dancer, courtesan and fantastic gardener” she was also a very ambitious woman. She did plot to land King Louis.
Personally, I don’t think this is really a negative trait of Pompadour’s – though I will say that one of the only recorded fights she had with Louis XV was when she left her husband. After she abandoned him to be King Louis’s mistress, her husband wrote her a long, admittedly overwrought letter begging her not to leave him. In what seems like an uncharacteristically mean moment Pompdour showed the letter to Louis thinking that he’d find it funny. Louis replied that was inappropriate and that “your husband seems a very decent sort of man, Madam.” Which, well, go Louis.
But, that aside, I do think the fact that she went after Louis indicates that Pompadour knew what she was getting herself into. Moreover, it indicates that she really wanted what she was getting herself into.
Madame du Barry had no idea what she was in for.
How could she?
Unlike Madame de Pompadour, Madame du Barry wasn’t hosting cozy salons for Voltaire to read his newest works before becoming Louis’s mistress. She wasn’t doing that because, before she met Louis, she was a prostitute.