By which you mean, of course, "write systemd units or whatever for the web and worker jobs", because you don't want to be starting your CI system by hand. That's not rocket science, but it's not quite out of the box.
That said, the emphasis on BOSH must really be hurting Concourse adoption. Nobody outside the Cloud Foundry bubble (which includes Pivotal) has any interest in using BOSH at all, and honestly, quite rightly so. It's cool there's a BOSH option for fans, but the primary deployment option has to be something accessible by the general public.
It did, I think. My gut feel from watching the Slack chat is that lots of people are deploying using the prebuilt docker containers. There are even projects that set up k8s clusters for you.