I was just reading the "Building Scalable Websites" book [1] released in 2006. At that time, "DevOps" was called SysAdmins. And there were also DBAs, Network engineers, among others.

> The way to do DevOps is to fire all of the Ops and then tell all of the Devs that they are now doing DevOps; you simply can't have it both ways,

I think this points at what happened: Startup scrappy culture started permeating new technology companies, which meant no budget for DBAs, QAs, SysAdmins and other similar roles. So decision-makers fired all those roles and ask Programmers to fill the voids. At the same time "cloud computing" started to mature, so there was a change from hardware/operating-systems tinkering to software related tinkering.

One just has to see the decline of "SlashDot" which was a very SysAdmin/Operating-System focused website, in favor of news.ycombinator and similar more software-oriented forums.

[1] https://www.oreilly.com/library/view/building-scalable-web/0...

A modern version of Cal Henderson's "Building Scalable Web Sites" would be nice to have. I'm sure a lot of it still applies, but it was written a decade ago: http://shop.oreilly.com/product/9780596102357.do