I do think you’re on to something here. Medium’s business model has to focus on attracting subscribers to pay the $5 each month. Without it, it doesn’t survive as a business.
But, there is a progressive challenge in keeping subscribers as well. Having a platform that churns out article after article is one thing, but building the social network another entirely. What better way than to feed retention and keep readers on the site by paying for responses?
I think Medium could get a win from this. The downside, of course, is that some writers would potentially earn less as some of the money would have to fund the comments pot.
Great article, BTW.