Then dotcom happened and every kid with a Linux box in their bedroom put themselves about as a SA. And in the 10s people think SAs who code is an amazing new invention.
And back in the 60s, IBM had "systems programmers"... Same thing.
The big difference I see in devops is that people started taking system management seriously enough to do first-class development rather than an afterthought.
I still am, but the "DevOps Movement" is here to point out that this artificial dichotomy is considered harmful.