I think the answer to that isn't inertia or greed. I would argue that the tools of federation aren't necessarily suitable to that specific problem. There is a difference between tweets and feeds compared to peer-reviewed papers in magazine-like journals.
That is, Mastodon does solve a kind of problem that is related to closed groups of individuals collaborating on a moderated topic. And it allows those closed groups to broadcast their work into a network and to selectively include elements from outside networks. You could probably use those raw tools to create something that might sort of work for scholarly societies.
But it does feel a bit like trying to shape the problem to fit the solution (put another way, if you have a nice new shiny hammer, suddenly a lot of problems start to look like nails). I think the article is trying to suggest that federation is a tool that is flexible enough to fill that role, but I believe a significant amount of infrastructure would need to be built on top of federation to achieve such a role. And also, a significant culture and process change would have to take place within academia.
Federation might be a part of a solution to the problem, but no where near the whole solution.