There are also people who I think are happy when they learn their leaders are corrupt

This, and actually it ties into the first point because even if the individual isn't doing such immoral acts, it normalizes the behavior among the population especially the ones who support those leaders. It's the double-edged sword of transparency. It doesn't necessarily help society to know that the ruling order is corrupt if good people don't have the will or power to overturn the order. Once everyone knows the system is corrupt and hopeless you just turn into the Soviets, or Mexico for a closer example. Maybe to some extent it's healthier for normies to live in ignorance and believe the smiling politician on TV is really a good family man who stands for true American Values. (as long as his crimes don't personally affect them)