The reason people fail to understand this is because they think of Feudalism as a political system, not an economic system.
But, politics and economics are merely two sides of the same coin. Feudal power derives from the ownership of Nature, and it is that power over land which makes feudal lords their own governments—monopoly on the legitimate use of force within a territory is the very definition of "government".
The American Revolution did not destroy Feudalism, it only gave us new masters.