Cause it's not FreeNAS. After 2 years with FreeNAS on my 45drives AV15 - I finally said f-it and made the switch. Boy oh Boy - Why didn't I do this 2 years ago!. FreeNAS made me sad every day. It made my shares sad. It made my laptops and desktops sad. If VMs on it would have ever worked - they would have been sad too.
Unraid allowed me to do everything that I wanted to do two years ago - and I allowed me to do it all in 2 days. 6 dockers running, 3 vms, 50+TB of storage online, a 10G switch for all of the clients, automated backups running, and even integrated with my DevOps slack channels.
Unraid really licks the lamas ass!