By failing to make a statement on capitalism, it necessarily assumes the two are not in conflict. This is a bad assumption.
The business model suggested in the article does not exist. Companies which distribute Free Software make their money by selling secondary products and services, like Canonical or Red Hat's support services, Firefox's Google search integration, or System 76's hardware, not by selling the Free Software itself.
The ultimate goal of the FSF is that all software should be Free. With that in mind, the question we must ask is this:
Why is there nonFree software?
The answer is the profit motive. Without the profit motive, there would be no incentive to make software nonFree.
Consider the examples Stallman cites as the inciting incedents of his entire Free Software advocacy career: Xerox's printer drivers and Scribe's paywall. Why did Xerox refuse to share its driver source code? To protect its profits. Why did Unilogic ask Brian Reid to put time bombs in his code? To profit from their investment in buying that code from him.
To ignore this is fundamentally a failure, or a refusal, to understand the conflict the Free Software movement finds itself in.