The reason there's no huge adoption of the Linux desktop is because there is no big company pushing its adoption for financial gain.
The Mac got a big following because Apple pushed it into the creative (and educational) space. Windows got big because Microsoft pushed it into the business world.
The MacOS comes free on all new Macs. Windows comes free on almost all new desktop and laptop PCs. It's a challenge to find a preloaded Linux machine. The average user doesn't have any desire to load their own OS.
I don't believe you'll ever see really widespread adoption unless Windows morphs into Linux (which in some ways is happening now).