Ugh. It is a bit like saying that people don't earn money to buy things, but earn money because they buy things! By this line of reasoning when I go to a store, I am totally unconstrained by how much I earn - I just take my credit card, swipe it and buy whatever I want. Now, this strategy would be unsustainable in the long run if not backed by sufficient inflow of cash from my employer. So I have to work every day. But these are totally separate processes!

A lot of bookkeeping gets done, assets and liabilities change hands, but in the end it can still be described simply as "people earn money and buy things with it."