I was a Windows user my entire life. I’ve only been using Ubuntu since April but there’s a few reasons why I can’t imagine going back.
Upgrading on Windows means buying a new OS and, in the case of Windows 8, getting used to an entirely new user experience. On Ubuntu I can use pretty much any UI I want and the experience is pretty much the same even if the back-end changes. Yes, moving to Unity would be a huge change from Gnome 2 but, unlike Windows, I can always move to Gnome 2 if I want.
That brings me to my next point.
2) Freedom and Choice
I can do anything to my system. The source code is available so I can modify it at the absolute lowest level if I feel inclined. I personally am able to compile my own software, including my kernel, to ensure that my OS is tailored down to the last byte for me.
3) The UI
I don’t get Unity hate. I love it. I have all of the shortcuts I could ever want (Super + W, Alt + Tab, Alt + Drag, Super + Direction) and it’s working very well for me.
I don’t really worry too much about my personal computer’s security. I compile a pax/ grsec kernel because I can, that’s literally 99% of the reason I do it. But it’s because I can do that that I feel more secure on Linux. AppArmor doesn’t have anything similar on Windows, AppContainer might possibly change this.
Windows is such a pain in the ass to update. Update Flash, update Java, update my browser, update Skype, update Pidgin – all of this has to be done individually and it’s a pain. On Linux it’s all handled automatically, which makes for a much easier and more secure time.
These are only a few of the reasons I chose Linux. There are a thousand little reasons. I keep Windows around for games and a few other reasons but I rarely boot into it.