The very argument that was posited by JCL creators about why it was a bad language is one that hits YAML very, very, very hard.

The creators of JCL admitted later that the original sin of JCL was that it explicitly tried to NOT BE a programming language. Everything "programmable" evolved out of real-world needs, creating the mess that it has become.

You can see it today with "programming in YAML", whether it is Ansible, Kustomize, Kyverno (K8s manifests get a pass because they are just serialization of non-programmable thing), or any other weird "we started to add functions to JSON/YAML dumps"

I keep thinking of writing a Terraform equivalent in Lisp. Would also be handy to replace configuration files.

I'd say it might be very similar to Pulumi or Chef.

From my own musings about making such a tool :)

One day Terraform will anger me enough that such unwise endeavour is inevitable.