As a society we might talk about virtue, but the reason we put it as a goal in stories is that in the real world, we don't reward it. It's not just that corruption wins sometimes, but we directly punish those that fight it. The mood of the times, if anything, comes from people realizing that what we called moral behavior leads to worse outcomes for the virtuous.

A community only espouses good values when it punishes bad behavior. How do we do this when those misbehaving are very rich, and attempting to punish the misbehavior has negative consequences on you? There just aren't many available tools that don't require significant sacrifices.