Yes you can't ignore MS, especially when they still dominate the desktop and workstation market with their OS.

I was a sysadmin in the 90s, and other admins I knew loved the Microsoft offerings - having gui control panels to server services. Active directory and the like. It wasn't particularly innovative, but MS managed to put lipstick on a pig and managed to sell it, while cleverly locking down their ecosystem through their proprietry platform. For some the CLI and Linux is still a turnoff, and there isn't that much preventing people from putting lipstick on that particular pig - but you don't see that many offerings (arguably you could say that Apple server is kind of like that).