The hermeneutic phenomenologist (don't ask) Paul Ricoeur started this whole club just for Nietzsche and a couple of unlikely compatriots: Sigmund Freud and Karl Marx. In order to be a member, you must: a) agree that religion is a crutch that we would be better off leaving behind; b) hold the belief that a great deal—if not all—of what we know is actually a lie; and c) eat a pound of cat hair. Hey, every club has its initiation rituals.
As for the "Suspicion" part of "Masters of Suspicion," well, these guys believe that behind every statement—no matter how innocent it may seem—there hidden forces at work.
Like all good Masters of Suspicion, Marx argued that what we think we know is actually an illusion. And like any good Master of Suspicion, Marx has his own take on what is responsible for these illusions: for him, it's economic forces. Just read Das Kapital, Volume 1 if you want to see how we're all shaped by economic power. If you're not tired out by 1,000+ pages of political economics, go ahead and read the second volume, too, but nobody's forcing you.
Where Nietzsche saw the "will to power" and Marx saw dollar signs (or, to be specific, pounds sterling signs), Freud saw sex, like, everywhere—and he thought it was responsible for just about every conceivable aspect of human behavior. Why do people drive BMWs? Sex. Why do men get hair transplants? Sex. When did the Great Fire of London take place? Sexteen sexty-sex. The list goes on.