Is this an attempt at humour I’m not understanding? The eponymous Personal Computer came out in 1981, and it came in an already thriving market with the likes of the Apple ][, Commodore Pet, TI-99, etc.
Heck some of the essays from Paul Graham date from the 90s.
It's hyperbole to illustrate that looking for people with 40 years of experience in personal computer is like looking for people with 10 years of kubernetes experience. You don't see any because they don't exist.
Well, there might be a handful stacked in the place the thing was initially created (they've probably long moved on though).
HN happens to be heavily centered around the valley and Apple/Microsoft, bad luck. Consider that the rest of the world can easily be a decade behind the valley.
There are many, many, many people with close to 40 years of PC experience. The k8s example is not analogous because the set of people with adequate experience is 0, while the set for PC experience is much much much higher than 0.
I'm not sure what experience in "personal computing" would entail as opposed to specific systems like Kubernetes. You could find someone with 40+ years of experience in Unix, C, or writing 6502 assembly code, with varying degrees of relevance to modern day work. Someone who has 40 years of experience with the 8051 or PIC microcontroller could conceivably be useful today, so if you wanted your grizzled old sarge, you could have them, assuming you were willing to pay enough money or had an interesting enough project.
Heck some of the essays from Paul Graham date from the 90s.