If you think Go was the first tool in the CD area, that probably says more about Thoughtworks defining CD as whatever-we-say-it-is, rather that the capabilities of a specific tool. It's not that people didn't do CD before 2010. It didn't bring anything new at the time. I suspect Go would have fared better if it was a Jenkins visualization plugin, there it could have ridden the coattails of its DSL system. Jenkins is the PHP of CI/CD and you need to go above and beyond it if you want to replace it. I would love, for example, to see Ansible/Red Hat bring their automation experience to this space. Imagine a CD Tower plugin, or a build system where not just the dependecies are declarative. I haven't had the opportunity to use Concourse yet, but I'm sure I will.
Have you tried GoCD? It has first class support for pipelines - not just via plugins, but built into the domain model.
Definitely not NIH. Many new tools in CI/CD space clearly acknowledge Go as the one of the first tools in the pipelines and CD area. While ConcourseCI looks good, even Jenkins 2.0 cannot compare to the first class pipelines support in Go.
Disclaimer: ex-thoughtworker.