A variety of reasons really. Privacy concerns, not having full control over my system with Windows, ads being pushed on my computer that I can't turn off easily, Linux is more fun to use and learn about in general. Last but not least is community. The community around Linux is fun to be a part of and makes me want to learn more so I can contribute in any way I can to the projects that I like. Once you start really checking out Open Source software and what it represents it's hard not to care about it.