I can see why the author is drawing this conclusion...

I wrote ASP.NET controls for a long time, and I see a lot of similarities in how I structure react components and how I would have written WebControls in ASP.NET.

I think in hindsight, my conclusion/realization from reading this article is that the lost opportunity for Microsoft was to re-invent the whole presentation layer with things like WPF and Silverlight, instead of trying to make it actually fit within the technology stack that people had settled on (HTML/CSS/JS).