They tried. But the irony is MS is more deeply ingrained. I worked a short stint in a shop that no joke ran Windows server to manage a whole floor of Macs using Active Directory. The only other Windows PC was a machine hooked to a large format printer. I spoke to the admin (dyed in the wool Apple user) who stated that as much as he loves MacOS, it can not match the features offered by Active Directory like AD controller replication.