Based on the readme in your project, yours does not include 1) a policy engine, 2) application proxies to limit scope of access to external systems/networks, 3) firewall configuration for commonly accessed package repositories, 4) configuration management, 5) credential management.

You do have some scripts that 'diff' package inventory of the one distro you support, but not a full fledged configuration management system to manage package dependencies, file permissions, services, etc. Technically the user can deploy one using your provisioning hook but since it's not built-in it's another component the user will need to bring with them, which is one more reason they can use any other system that does basic sandboxing. I'm sure it's useful for you, but it doesn't do anything all the other solutions don't already do. You basically made Vagrant but without the useful Vagrantfile and OS-agnosticism.