Why do some Americans like to compare Queen Elizabeth to a tyrant?

I have heard Americans compare the Queen to the likes of Kim Jong il and compare the UKs political system to the Chinese communist rule. How can you say the UK isn't a real democracy. Ok there is an "unelected head of state" (who doesn't actually do anything politically) who is really there just for formality and tradition. And also say that she steals our money? The Monarchy works as a business which brings alot of money into the Treasury...