I had the exact same reaction to Medium’s recent changes about paywall and curated content. I hate it.
I publish all of writing to publication and almost all of them want only free-to-view articles so they can reach as wide an audience as possible. Which essentially means the (now default) option to make my stories members-only (and a chance to be curated) is not an option for me. Which means I will never have anything curated unless I stop submitting to most of my favourite publications.
Publications (like The Startup, which I write for too) are what give new writers a chance to gain wider exposure and audience growth. But if publications are against member-only stories, and most writers are against it, who’s in favour of it? Anyone?
Only those who are here to earn money will be. But as you said, many writers (myself included) don’t write on Medium to earn money directly from it. That’s not even a consideration for me. I don’t care if I earn nothing from my writing here. But now that Medium is so money-focused, it’s killing the experience for readers, and for any writers with agendas other than income.
It’s a real shame.