Well, by that definition any economic system you name is prone to wage slavery, certainly including American capitalism. It's a sad fact that all over the face of this planet (and particularly in industrialized societies) most people hate their jobs and do what they do only to make a living and keep body and soul together. In most cases it's not actually the fault of the system but, rather, the fact the people in the system have no particular marketable skills that would make them enjoy the work they have to do.
The problem is not with capitalism. I'm sure that there are just as many people in Castro's Cuba and in No. Korea who hate what they do for a living and have a hard time making ends meet. This world is not a Utopia, no matter under what economic system you strive to make a living.