There are millions of combinations of motherboards, sound cards and video cards. There are on board video chips and onboard sound chips and standalone versions. Many distros and kernel and driver versions. There is KDE and Gnome and Xfce4 etc. And ALSA, Pulseaudio and Phonon.
Your particular combo may be working OK for now, and good luck to you. In my experience the HDMI audio driver often (but not always) causes grief whether from the fglrx or xorg-radeon drivers and across three different disros and multiple distro versions.
Sometimes you can run with your sound card not as soundcard 0, but eventually something breaks.
All we need is a simple way of saying to the setup do not make an HDMI sound device please. This can be achieved through xorg.conf entries and editing alsa-base.conf, but that is not simple for beginners. Plus xorg.conf is meant to be disappearing.
Thats the point. If therere many people using Linux as a server, then Windows Server can well take its place in the market as a Hypervisor product, even if people move away from Windows Server to provide regular services.