Well not blow your brains out difficult but "learn a new syntax, behavior, rules, depend on a new package" difficult if a few shell commands is all you want to do.
I can see where they are coming from. I can go a long way just using shell script to configure (and yes, you can make them idempotent too).
From your site:
> You already have a religious passion for a particular CM tool
Aren't you doing the same against Chef and Puppet then? It sounds like. Oh "comparison" -- yeah just use Ansible.