I think it’s getting traction not simply because it’s negative/bitchy, but because it addresses problems other people are experiencing, too. I call it the Medium meta effect. Or something. Write on Medium about something that happens on Medium and people respond. Because they experience it too, and lordy knows, we can talk to the walls all we want, THEY don’t answer.
Heck — write a post with the title “hey medium, I have a question” and they still won’t answer. So we talk to each other instead.