Not zealotry. I'm not a fan of having to install extra software such as Ruby or other agents on every server. If I can't manage every server with the tool, then I continue using what I do now or look for a tool that doesn't need an agent. Heck, security requirements make installing extra software a bear due to dependencies. I have to manually install and chase down the additional packages. We have quite a few older systems which don't support these agents, even cfengine. So having an agentless tool to do configuration management is the goal. I am considering Ansible but if it doesn't work, I'll continue to use my ssh based scripts.