You're right. And, that's just wrong. We shouldn't be paying people who don't support the system. That's an injustice.

Here's what I found: "No, you don’t have to be a paying Medium member to join the Partner Program and earn money for your writing. Being a Medium member doesn’t influence how any work is published or featured through the Partner Program—it simply allows you to read paywalled content published by other writers, and support their work. Learn more."

That was under "Common Questions" at this link: https://help.medium.com/hc/en-us/articles/115011694187