Some good answers, but I also want to point out that this isn't actually a universal need.
I think that our social nature, and the way most societies and communities work (particularly in countries that subscribe to exceptionalism) makes them prone to developing these feelings, but they very much are not universal and can even be unleaned.
Presumably because mania is a key part of the cult, and many portrayals in media use the behavioural signs of mania to convey evil.
Although I'm sure plenty of people might look a little manic if they were pictured while handed a lot of money with a big debacle made out of it.