It's stability vs reliability. I know Arch is reliable enough that I can depend upon the community to take the right decisions, Find what I need in their unparalleled documentation, Find bleeding edge binary packages of open-source tools in the community repo etc.

Yes I occasionally don't know what's causing a problem and I have to reinstall some packages. It's definitely not stable.

But if I needed stability I would have gone for Cent OS or what ever stands for stability nowadays. And that's the beauty of Linux, There's something for everyone.