Rabbi Chaim Shmulevitz attributes this development not to a more hateful generation of Egyptians but to a change in Jewish identity. Joseph et al possessed a dignity and clarity of identity that set them apart. The uncivil Egyptians would have decreed decrees in Joseph's day but it didn't occur to them to do so because the Jews occupied a different plane. Subsequent Jews lacked this clarity; living in a comparable realm to the Egyptians, they became susceptible.
R. Shmulevitz applies this idea to being free of subjugating and destructive inclinations: the greatest protection we have is a sense of dignity, an inner knowing of our immutable worth. We might succumb to such inclinations, but our actual dignity remains intact, ready to awaken.
This explains why we speak to witnesses in a capital case about the dignity of man. When witnesses testify in a Jewish court that someone committed a crime worthy of death, even after a thorough vetting of their testimony, we are concerned they're lying. The court thus reminds them that Adam was created alone to teach us that a single person was worth having created the whole world.
How do we draw them away from the ledge of the cliff of false testimony? Not with threats that G-d's going to get them, but with the message of their dignity: "what you possess is precious, don't sully it."
Even one occupying a low place is close to inner exaltedness. Relating to the dignity in ourselves and others is the greatest resource we can offer.