What are some criticisms of Keynesian economics?

Is it true Keynesian Economics doesn't work and is full of BS?

• I remember this guy once told me : "Be careful what you read on Economics.There's lots of BullShit such as Keynesian Economcs" In another chat he went on srpouting how Keynesian Economics is impractical,does not work,and is full of BS. Now FYI the guy I'm referring to brags that he's a Degreed Economist and a Diehard Libertarian who fullheartedly believes in and Wishes for the existence of the "Free-For-All Libertarian Economic System". Yahoo Answers Economists what would you say?Would you say Keynesian Theory is impractical and doesn't work in the real world, and is full of BS like this self-proclaimed Diehard Libertarian Economists rants? Also I noticed that every Libertarian I met so far and Libertarian Websites and Blogs I've been to always bashes Keynesian Economics as Impractical and Full of BullShit!Why do Libertarians generally hate Keynesian Economics and opposed it adamantly,always ranting its BS?

• Answer:

  Keynesian economics is BS because what it's basically saying is that the government can make society richer by printing money, and using the money to pay people to dig holes and fill them in again. When you strip away all the mathematical jargon and gobbledegook, that's what they're saying. Now it's obviously a) wrong, and b) what governments want to hear. So governments then go on an orgy of spending, wasting money the mountain, and it causes enormous economic damage, and enormous social injustice. Then the idiots who voted for these people say "That's free markets for you. What we need is more government intervention in the economy." So it's not just idiotic - it's more corrupt and destructive than that. Because it's precisely government playing jiggery-pokery with the money supply that causes the depressions in the first place! Also it gives economics a bad name, because people just assume that it's intrinsically a BS subject used as a cover for governmental foolery on a grand scale. Whereas in fact economics has enormous explaining power, and as it happens, most of what it is able to explain is that the pretensions of government to make society richer by tax, debt, inflation, handouts, bailouts and war, are downright FALSE. A good plain-language introduction to the topic explains why: