My biggest problems with the article
a) He's talking about "PHP" and referring to old versions of plain vanilla PHP. He also talks about The Event Loop like it's a Node only thing: There exist such things as ReactPHP and Icicle which implement the concept.
Modern PHP also comes with constructs to help with an async design
b) Node doesn't include websockets support by default either, and the comparison is made against Ratchet when it could have been made agains hoa/websocket which is both more idiomatic and nicer. As a sidenote, check them out, they make nice things.
And finally, the author marks an advantage in sharing environments when talking about languages, not runtimes. Which in and by itself is more of a curiosity.
While it could be possible to inject a PHP runtime in the frontend (and some projects like the RippleSDK somehow did), it wouldn't make sense; they don't really have the same purpose or origin, one was born in the frontend and shoehorned into the backend, and the other was born in the backend and stood there.
The way I see it, it's ultimately a matter of added value.
Why doesn't anyone actually make an Icicle vs Koa comparison? Or maybe Symfony vs ROR?
There is very little to learn from putting a toolkit (or even just the amount of tooling) against a bare language, and when people do it over and over and over it becomes clear it's just a disingenuous attempt to make the X in "PHP vs X" look good.