Not quite the angle the author was getting at, but have noticed at $dayjob that staff who are able to do some incredibly complex automation against Linux-based

Not quite the angle the author was getting at, but have noticed at $dayjob that staff who are able to do some incredibly complex automation against Linux-based stacks, containers, etc. - get quite lost when something low level isn't working right. Gaps in understanding of OS level troubleshooting and concepts gets them stuck. You're wise to keep staff around who understand the low level stuff, in addition to the shiny new abstraction based tools.