It's worthwhile to me at this time because I like knowing that the people I read get more out of it. I like supporting other writers as I can, and this is one way to do that.

For those folks you mentioned, I doubt they have time to read much on Medium these days. It seems like this site is just another way to funnel readers/potential clients from here to their website or mailing list so they can have a better chance at selling their courses. I don't fault it at all, they're doing what works for them and that's great. But I think they may not have opted into the program because they probably don't have much time to read on Medium anymore.

That's my outsider guess though. Who knows?