Methinks you might be mistaken.
...source, please?
Wikipedo: Since November 2017, all of the world’s fastest 500 supercomputers run Linux-based operating systems.[6]
[6] “Operating system Family / Linux”. TOP500.org. Retrieved 30 November 2017.
“MY mistake” was forgetting nits exist to be picked.
Watch the video. 1hour, 50 mins. (No breathing exercises discussed, either.)
I don’t recall who said it, or if the attribution to the “500” Super Computers was even mentioned, and given the weight of the video reveals, I had no idea anyone, anywhere, would care. 😳