Not so much a NEW idea as a problem with the current auto-provisioning after a Joomla one-click CMS install.
The issue is that the auto-provisioning fails.
The auto-provisioning works when no CMS is chosen. We don't know if it works with other CMS one-click installs as we don't normally work with them.
Joomla does not require any additional/special provisioning requirements, so if the auto=provisioning script works without a CMS installation, it should also work with a Joomla CMS installation, but it does not.
I believe the issue may be an issue that there is something wrong with the auto-provisioning script that is being ran after the one-click CMS install of Joomla (and possibly other CMS;s, too).