Audio with CD player - why is the cable necessary?

hello all,

i've read the threads about needing to use an MPC-to-soundcard
cable to enable direct CD audio playback (e.g. with XMMS). but
i'm wondering why it has to be this way. direct playback (without
the cable) works in WinXP, so it is certainly _physically_ possible.
the DVD client i just set up on this same machine (videolan) gets
sound to the soundcard without a cable as well. so is this simply a
question of someone doing the appropriate coding,  or are there
patent/licensing/philosophical issues involved?

<mini-rant> seems to me that if linux is to be more accesible to
novice users, it is not reasonable to expect them to know that they
will need additional equipment to do something this basic, let alone
what specific equipment that is or how to open up the box and install
it. that last bit, in particular, is a significant obstacle to passing the
"mom test." (not that my mom needs to run linux, but still... :) )
</mini-rant>

cheers,

SM

p.s. is saw a post from alan cox saying that there were players (not
the ones included in RH by default) that could do this, but i haven't
been able to find one. any suggestions?