This has been an outstanding issue on all platforms including Linux. I
read about this in Linux Unwired. My take on it is that Broadcom feels
that they have a competitive advantage, and documenting their stuff,
would compromise that advantage. That's only a theory from discussions
with my UNIX Admin buddies. :-)
That's one theory, and another is that the WiFi manufacturers don't
want to allow hackers to modify radio power settings or they'll
lose their FCC licenses for the product.