He left out Cfengine. That's a big gap. It's been around since 1993. He also focused on package management and the provisioning process. I feel like there is more to automation than that. Continuous deployment, process management and distributed scheduling come to mind. As a plus, he does seem to get that just using system images (like Amazon AMI's) can be pretty limited.

I think the complexity of automation is more a symptom of the problem space than the tools. It's just a hairy problem. Computer Science seems to largely focus on the single system. Managing "n" systems requires additional scaffolding for mutual authentication and doing file copies between different systems. It also requires the use of directory services (DNS, LDAP, etc…)

I like the analogy of comparing the guitar player to a symphony orchestra. When you play the guitar alone, it's easy to improvise, because you don't need to communicate your intent to the players around you. When a symphony does a performance, there is a lot of coordination that needs to be done. Improvisation is much more difficult. That is where Domen is right on target, we can do better. Our symphony needs a better conductor.