Lets put it this way. Suppose you have six castaways on an island, five of which are Asians and one American. One Asian works to fish, another looks for vegetables, another hunts for land animals, another is the chef, the last Asian builds the fire, and the American does nothing but eat and tan all day. The Asians work every single day to feed the American, who operates his own tanning service for himself. The Asians are allowed only a bit of food to have enough strength to start the process of building the economy again the next day.
Now, Keynesian economists will tell you that if it wasn't for the American, the Asians would all be unemployed. But obviously that's not the case. The Asians are the ones driving the economy's growth and sustainability, while the American just operates a service sector for himself.
If you were one of the six Asians, would you rather continue working hard for the American so his service industry to himself can prosper, or would you rather kick him off the island so you can enjoy less work, more leisure time and more food? The answer is obvious.
Obviously, it's more complicated than this in a multivariate open economy, but this example will suffice.