Under System->Utilities the only default tool is Yum Extender, where previous versions had a user management utility. It's not entirely clear that this GUI is called 'system-config-users' so adding it post-install is not that straightforward.
I think adding system-config-users to MATE's comps group is a good idea. Also system-config-language if it fix for f19.
Fixed in comps. run "yum distro-sync"