This paragraph from Warren over at Coyote Blog may well be the best paragraph I read all week:
"For socialists, wealth is not created by man’s mind and his effort — it is a spring in the desert with a fixed flow rate. It just exists to be taken or fought over. The wealthy, by this theory, have not earned their wealth, they are just the piggy ones who crowd to the front of the line and take more than their share from the spring. Unfortunately, socialists have never been able to explain why the spring, which flowed so constantly (and so slowly) for thousands of years, suddenly burst forth with a veritable torrent in lockstep with the growth of capitalism in the west. And why it seems to dry up in countries that adopt socialism."
The fallacy of treating the world as static, rather than as a dynamic system, is a common one; it affects not only socialists, but every person (including many entrepreneurs) who don't seem to realize that Newton's Third Law is almost universally applicable.