I disagree, I've never used jsx and I can still build web apps. There are plenty of templating languages to choose from, my choice is Jade. I actually have never touched React because I've never had so much DOM manipulation to make use of it. If anything I can smoothly update my DOM with marionette/backbone and a little css animation.
What are you disagreeing with exactly? They're not saying you can't build web apps without React and if you haven't even used React I don't see how you can make any judgement on that part.
Yeah, but the thing with React is that it's one library, instead of having both Jade and Backbone, you can have a fully React stack and have peace of mind through it.
I've used Jade and honestly prefer the React way for sure because it combines the javascript with the html in the same file(s)
