Because they've set out to learn it. They've learned to use their tools.
> On the opposite, the knowledge of these things doesn't turn you in a
They're part of the tool set. Just like a Windows user might have to
learn to do some arcane non-music thing to make it work. A professional
learns how to do them. A smart professional learns how to do them in
such a way that they don't have to do them again. ;-)
A lot of that setup stuff is already dealt with by audio distributions
now. The only "setup" I had to do with Musix on my little effects box
was tell JACK which audio interface I wanted it to use. I fiddled with
period and such settings until I got a latency that works for me without
xruns. That was just experimenting a bit. Gave me an excuse to play with
stuff along the way. ;-)
> We must admit that win and mac "music-woriking-curve" is musch easier
Having watched my musically-capable but technologically-inept friend try
three times to get and keep professionally-setup Windows audio systems
working ... no. It's not easy on the other platforms, either.