I’m sorry to burst your bubble but:
https://dictionary.cambridge.org/us/dictionary/english/whodunit
https://www.dictionary.com/browse/whodunit
The mystery in question specifically refers to a crime, usually a murder specifically and who committed it. Hence the “who” in “whodunit”. Thats why they don’t call it a “Whoisit” or “howdoeshe”
We have always known why Hitler rose to power, and we know why Trump was reelected. When people are economically depressed and a man comes to you and tells you “This isn’t your fault, I will persecute those who are responsible and personally make things better for you.” It’s human nature, out of fear, frustration, or desperation to grasp that hand. We as a people are not ready to trust the guy who says “This is our fault, and it will be hard, but we have to fix this together”. Take everything you know about Hitler and Trump and OUR world out of it, take out your reasoning and tap into your monkey brain for a second and simply ruminate on those two propositions. Which one would you rather be true? You can’t honestly tell me the latter. You may know the latter is true, but it would be so much easier on you if the first was true.
Like it or not, we aren’t as evolved as we like to think, and those of us who consider ourselves enlightened are vulnerable to our lizard brains at one point or another.