Arch is the primary distro that runs on my main system. I do use openSUSE, Ubuntu, and Kubuntu on it and switch between them from time to time. But I spend the majority of my PC time on the Arch system because I find it to be an excellent distribution for advanced, and new, Linux users. In a nutshell, I am hooked on it. And there are reasons for it.
The bigger question is, why did I choose Arch Linux over others and what does it have to offer that others don't.
#1 By the community, for the community
One of the strengths of Arch Linux is that it's a pure community driven project. It doesn't have to worry about the market, customers and ROI, which can affect its development -- and could, in fact, derail it.
I am not even aware of any organizational structure of Arch. The Arch page clearly says "Arch Linux survives because of the tireless efforts of many people in the community and the core development circle. None of us are paid for our work, and we don't have the personal funds to sustain server costs ourselves."
What they do have are release managers and maintainers of core components such as pacman and main repositories, but beyond that it’s all for the people, by the people. And this has been working quite well, as it turns out.
Arch Linux doesn't patch anything....