Windows is unsafe by design, and macOS isn’t a lot better. But even Linux distros that have joined the mainstream by becoming less scary are much safer.
Windows has many exploits and backdoors in it. It is not just the NSA Prism backdoor, but other things. An employer I worked for had used Windows because they could use a backdoor to spy on employees and add it to an Windows Server login script for their domain. They even had to hide it from the AV program to make sure it wasn’t deleted by mistake despite being spyware.
GNU/Linux or Linux scares them. There are no exploits to use, no NSA backdoor, Linux is secure and respects your privacy. As Richard M. Stallman claimed GNU/Linux and other Free software are Free as in Speech that they respect your freedoms and rights. Commercial software collects data on you and Windows sends telemetry data back to Microsoft based on what you do.
The Windows monopoly makes sure that Businesses and Video Gamers stay on Windows by not porting their software to GNU/Linux. They might port it to MacOS because even MacOS has backdoors and exploits according to Prism Break. https://prism-break.org/en/categories/macos/
GNU/Linux comes in many different distributions. If you don’t like one, there are hundreds of other versions to choose from. Linux is more secure than Windows, and like MacOS it is based on UNIX standards. Most Dotcom Startups use a version of Linux for their servers like Debian, Ubuntu, or Fedora.