I find myself agreeing with the article (although I also agree that it assumes you've chosen an SPA when you shouldn't have). To add my own perspective:
I work on an app, the front-end of which essentially consists of 6 nav tabs, 3 of which show an index of records with corresponding add/edit forms. We don't have any hyper-fancy interactive components that would require heavy JS libraries. And yet... we develop in React.
Yesterday, I needed to add 1 new field (representing by a checkbox input) to both our app and a corresponding back-end application we have, which uses Rails views.
I checked the git logs after to see how long each took. The Rails view took me literally 2 minutes to update (add field to model, add field to controller, add input to HAML with a class on the parent div). The React view took me 52 minutes, plus I later found out that I'd forgotten a damn type on some interface that's a shallow copy of our model.
Is this a problem with React itself? Not really. But it's a problem in the way that it's used, and our 6 nav tabs and 3 forms don't need all the overhead of React. So for people in a similar situation, this article really rings true.