I think people don't realize that Medium doesn't require articles to be behind the paywall. There are two ways an article gets paywalled:

1. You opt-in to getting paid for views.

2. If you put your article up for curation AND it gets picked. If it gets picked to be shown in curated feeds, it goes behind the paywall, but if it doesn't get picked by a curator, it's openly accessible.

If you don't select getting paid for views or put it up for curation, it's always openly accessible.

I use Medium because hosting my own blog would be too much of a hassle. I never put my articles behind the paywall; my aim in writing is not to get paid, and I don't put them up for curation because I don't have an explicit goal of increasing my readership.

I'm also a Medium member, because I do think we need ways of paying for content, and paying for good content (the curation part). Maybe Medium's model is not the best way to do that, but I'd rather support a company that's trying to find the right balance than declare that all content should be free.