It is called pasuspend, but its seldom used as things work just fine by default. Also, you are full of lies:
https://help.ubuntu.com/community/In...ion/MinimalCD/
Short story? Don't like it, don't use it. Use your fav distro and let others use theirs. To each their own.
My experience with PA is that it works just fine (Using Xubuntu 12.04). I run wine games (Ie. Skyrim, Civ4, etc) with sounds playing along with media players and web browsing (youtube et all) and it all works as expected, simultaneously even. I have reproduced the same experience in various different machines; you might have a particular problem with your setup.
Valve doesn't need to do any disabling because the stuff works fine. What they might do is customize the interface for their own needs if they go with a linux console or games distro and need a much simpler interface; Ubuntu TV style.