" They reject capitalism because nobody has been able to explain how individuals, acting to further their own self interests, can raise the economy of the entire population."

Adam Smith discovered that before America even existed and it has been backed up by hundreds of years of economic science.  Seriously, you should take economics 101.  This is not even something that economists actually dispute, from Paul Krugman to Ludwig Von Mises, the fact that markets work has about as much evidence as gravity in terms of consensus.  

Every single society that has tried to exist without markets has failed.  Every single one.  China and Vietnam only became wealthier after adopting market-based systems and the same is true for literally every country on the Earth.  You are so categorically wrong about this particular issue that you can't possibly come back from it.  Seriously, just read an economic textbook, freshman level is a good place for you to start.