Non-rolling releases might work with smaller software where your distro maintainers can backport security bugfixes easily, but as soon as your software gets too big and complicated the distro maintainers won't be able to backport fixes themselves and will have to just resort to packaging the latest version of certain packages (like Debian had to do with Chromium and Firefox).

Also, for the most part, the "Arch is unstable" thing hasn't been true for a long time. I find that it's far more stable than Debian or Ubuntu LTS on my machine because of newer kernels containing newer hardware drivers.