To me it doesn't matter what React likes to think it is, to me as a front-end developer all that matters is the tool that I choose can do the job. React is just another tool, in a way it is like jQuery: it doesn't do everything and it shouldn't be used for things that need something else more full figured or suited for the task at hand.

I think Facebook do a great job explaining what React is and as far as I am aware, they don't go claiming that React.js is a 100% reactive library. There are no unclear intentions, Facebook saw a need to improve DOM performance and they achieved it in a great library that I think is a pleasure to use.

I have built two projects solely using React and the Flux architecture. I don't have exact figures, but it saved me a lot of time compared to using something like AngularJS which has too many conventions and opinionated ways of doing things. I was able to get a nice performant CRUD application running in the space of a few days, most of the time was spent creating the API and getting it to return the appropriate data.

How can you write off a library like React.js when it goes beyond just another open source project, and unlike Google with AngularJS, Facebook aren't dogfooding their own product and they are actually using it for parts of Facebook, the Instagram website and a few other places. React.js is a battle-tested library. Those who have used React.js on a proper project know that it is very easy to use and its performance is better than any other SPA framework by far. Unlike other frameworks and libraries, React.js can back up its claims and has proven benchmark after benchmark it can render UI components extremely fast and efficiently (with a concentrated effort to make it even faster).

Sure, React might do things differently and it might not be a pure form of reactive programming, but it works and it works very well. Coupled with Flux, you actually do get a nice and reactive development environment where events are emitted and things are updated throughout your application from your stores. I don't really see Flux being mentioned in the slideshow which is a shame because Flux is the missing piece of the reactive puzzle.

It's easy to say something sucks without really giving an adequate reason why it sucks. Seems like the author had a bad experience with React or perhaps just wanted to ruffle some feathers. I also got the impression the author was trying to pedal their own library Cycle.js which will no doubt be abandoned in 12 months time when it doesn't get as popular as he would have hoped. Nice try, but not a very well thought out argument in my opinion.