Windows is a privacy nightmare. The OS is constantly sending data to Microsoft while being used.

Windows hogs resources. If you don't shovel money out for new hardware every few years, your computer will run like shit.

Windows is full of ads.

The majority of malware is written for Windows. Not really a selling point for me, but it's a bonus.

Linux is free.

Linux doesn't force updates. You update when you want to, and it takes less than a minute to do.