That spin-zone assertion is not even wrong. I saw nothing wrong with MadseasoN's statement, and I'd be considered a libertarian by most people.
Beware mate. You'll be lumped in with all those demoncrats for that kind of thinking. Only America-hating terrist simpathizers that want us to accept defeat talk like that. I don't really believe that garbage, but just look at right-wing blogs or Fox News videos. You'll see a disturbing trend, only when it's politically convenient (read: some "outrage" happens that makes it politically acceptable) do they say bad things. Often, and especially during campaigns, will they trot out the "defending America" sloganeering. Don't yell at me for it, yell at the right-wing echo chamber. They started it in 2001.
Your signature is annoying because Marx didn't live in the 20th century and his influence on world society began in the 19th century. Furthermore, the writings of all four directly and indirectly influenced the lives of hundreds of millions of people. This is an inescapable historical fact. It does not matter that you think they are overrated, however many times that opinion is repeated ad nauseum.
Hence modern age and 20th century. I'm describing the relative impacts. I'm actually doing Rand a favor calling her a philosopher, rather than the pedantic zealot she was.
In either case, they are both wrong. One seems to think that the world of unicorns and rainbows comes from everyone being equal. Bzzzt! Human beings (human behavior) won't allow it, as best demonstrated in the real world by Stalin. The same holds true for Rand, except her world of unicorn and rainbows was "going Galt" as people put it today. Still, just as stupid because without a strong government, you get Somalia. A bunch of individuals that kill each other, because fark you, I got mine. Again, basic human behavior.
As far as Friedman and Keynes belong, the world has changed. Sorry to say it, but we've moved beyond the economies those two were familiar with. Their theories are, in the best cases, tangentially relevant. More often than not, however, their theories will fall apart. See: Cutting taxes and no job growth, for 10 years. See: Putting money into the system for neglible effect.
The fact people still cling to Marx or Rand is just a blatant and willful blindness to the basic nature of human beings.
The fact we still hold onto Keynes and Friedman's theories is a result of stubborness. They worked before, so they have to work now is the idea.