We do not understand that persons get money because they are part of society. To understand that is to begin to appreciate the present author's unique contributions to understanding economics.
What is really controversial here is to acknowledge that originally (which is to say in the case of developing phase capitalism) this had ethnic aspects. This is true, even as it is also true that this kind of ethnic limit was being stretched. Until recently, those in a capitalist system usually dealt with members of their own clan, tribe, ethnicity, etc.
By "usually," we mean in a demographic sense. This is perfectly appropriate, since actual capitalism always develops in reference to a whole society (an ethnicity, or proto-ethnicity, or only-temporary ethnicity).
Capitalism, of course, slowly "self-destructs" (as in the Schumpeter material) its own ethnic context, but the point I am making is that it does exist within ethnic parameters, for a period of time, which is what I call the "developmental" period.
Thus, to return to the theme, we get money as members of our society.