I am a little naive about this stuff. What is the incentive for these kinds of comments? Is the idea that you'll read one of their stories or something?
I have to say I don't always "engage." By that I mean, I will read and clap, but sometimes that's it. If Medium's full definition of a read includes highlighting and replying in addition to clapping, that's a flaw in the Medium payment reward system. What if I have nothing much to say? What if I just forget to highlight? I do forget. I don't read Medium stories, necessarily, with the thought that I should always highlight the damn things.
Also, what if I don't like someone's opinion? It doesn't happen often on Medium, but I can see not clapping if someone takes a position I am against. But they, as writers, should still get credit for the view I give them.
Honestly, I'm not even particularly fond of the "Friend of Medium" thing, even though I am one.
In other words, I think Medium's engagement process for paying writers is fully, and completely, broken.
Oh, by the way:
Great article!