It doesn't mean that the “self made man” didn't benefit from the existing infrastructure.
The left is desperate to tear down concepts of self reliance and personal achievement. All good must flow from the state, not the individual.
If the left wins the argument that nobody is a "self-made" success, they have successfully argued for communism.
Since, in their belief, nobody is successful without help from others (family, infrastructure, etc.), they can say, like Obama said, whatever you have, you don't own. That is the communist argument.
And what you will end up with after all wealth is confiscated by the state is a country with 99% of population doing as little as possible. The country will swiftly descend into an American Zimbabwe.