Tracking down usage of libvirt
Solution 1:
libvirtd can be installed if virtualization is specifically requested as a feature. It may also be installed if the person doing the installation chose "Server with a GUI". In that case it's expected to be there, even if no VMs were ever created.
You can see if any virtual machines exist by:
sudo virsh list --all
The defalult directory for storing virtual machine disk images is /var/lib/libvirt/images. You may check for disk images in that directory.
If no virtual machines or virtual disk images exist, then it should be safe to remove libvirtd.