In the 1980s Reagan adopted the IBM PC (open standard) running MS DOS (proprietary OS) as the standard desktop PC for the US gov. When the US gov says that all it's employees will have a IBM PC running MS DOS on their desktop it's kind of hard not to be dominate in your field.
No one will ever need more then 640K ram. Bill Gates.
You just reminded me of something I once said to my now (thankfully!) ex-wife:
Dear, it has 2mb of RAM, a 20mb hard drive and look, a CGA color monitor! I'll never need more than that!
(This post brought to you courtesy of an AMD 3700x w/32GB Memory, SSD RAID Array for virtualization and booting multiple OS' and 10Tb of storage and 2x32" 4k monitors.)