I think in the context of that link, they see React as a failing of the web. If the W3C/WHATWG/browser vendors had done a reasonable job of moving web technology forward, things like React would be far less necessary. But they spent all their time and energy working on things like <aside> and web components instead of listening to web developers and building things that are actually useful in a web developer’s day-to-day life. Front-end frameworks like React, on the other hand, did a far better job of listening to developers and building what they needed.

One of the biggest flaws of the current web technology stack is the unholy mix of concerns with respect to layout. Layout is handled by CSS and HTML in a way that drives people crazy. I recently wanted to have a scroll bar for super long text inside a table cell. Easy, right? Turns out you need to change the HTML to include a <div> inside the table cell, since there is no way to style the table cell itself and have it do what you expect it to do.

XLST doesn't solve this at all, since you're just generating more of the problem, i.e. more HTML and CSS. It feels like there should have been some sort of language exclusively for layout definition that doesn't necessarily know about the existence of HTML and CSS beyond selector syntax.