I got Ubuntu recommended by an electrician back in 2005 or 2006. (I used to be using Red Hat/Mandrake/Mandriva back then.)
Soon after I realized it had come to the point where Ubuntu was not only possible to install and use but simpler to install and use than at least OEM-loaded Windows machines.
It seemed to work well for grandmothers, kids and sysadmins.
Notable exceptions:
- certain people refuse to learn (certain Windows sysadmins)
- people who depend on powerhungry software that doesn't exist on Linux (for less power hungry software there is RDP or Citrix and Windows Terminal servers.)