What a weird opener; if there's a topic that's plagued by anecdotal evidence it's this.
Bit of an odd opener, but at least the author backs it up.
The big reason why gaming may look terrible at 30 fps mostly has to do with temporal aliasing, in other words, the lack of proper motion blur. For example if you look at a car going quickly from left to right in most games, you will see multiple copies of the car instead of a smooth trail, as if it was shot with a strobe light. Modern graphics engines can do motion blur but it is a hack. As an experiment, I tried doing it properly with very simple objects and it definitely looked smooth even at low FPS.
But there is a caveat. While it may look good if you are just staring at the screen, things start to fall apart when you start tracking objects with your eyes. The blur becomes apparent. You then have the option to trade blurriness for smoothness by adjusting shutter speed. It is the same kind of trade-off you can have when resizing an image: blurry or pixelated.
And then, there are jitter, tearing, artistic considerations, etc...
It's probably a fairly fitting opener given that it then dives into perception of input latency, which is a less common or discussed topic.