The author assumes that humans can't feel the difference between 100 and 200 ms latency, which is simply not true. When I had to move from gameport MIDI interfaces to USB ones back in the day, I could immediately feel the added latency, which was just a few milliseconds more, not a hundred or worse, but to a musical ear it was clearly noticeable. They also only measure USB and wireless devices (that is, USB and USB+wireless ones, since the dongles use USB) which of course are the main limitations wrt latency. Those keyboards can't beat for example any PS2 based 30 years old keyboard because the PS2 port was essentially an UART directly connected to the system bus, without any of the overhead a complex protocol such as USB would add. To me very low latencies can be obtained with USB too, but that would likely require a total rewrite of the drivers and engineering keyboards to take advantage of low latency drivers just like USB music keyboards do.

Edit: please disregard any attribution to the author of the false assumptions about human latency perception; that was a citation from other sources they were also refuting. Thanks to all HNers who corrected me.