I rely on my desktop more than I rely on any given server
Sure, we probably all stare at our desktop machines for hours a day, and only poke at our servers for a few minutes each day. But, an hour-long outage of my primary server will effect hundreds or thousands of people. An hour-long outage of my desktop will effect only one guy. I'll spit and sputter and curse a lot, but it probably won't cost me business or customer good will.
That said, everytime something breaks on my desktop machine running Fedora, I think "Hmmm...maybe I should be running CentOS here."
Well, a certain commented-out line in OpenSSL comes to mind :-)
But seriously, I refuse to run anything other than Debian Stable, Ubuntu LTS, or a stable BSD tree on my home systems. I rely on my desktop more than I rely on any given server, so why would I put something less stable on it?