Apple's Darwin commitment

I keep getting the impression that Apple doesn't release a darwin iso 
for any real purpose to be used.  So few computers are able to run the 
latest release that it seems unlikely to be released for bug finding.  
It's not exactly practical to build it.  Apple seems to hold a lot of 
things back that are almost necessary.

In Apple's developer documentation, they state:

"The Darwin layers of Mac OS X are open source. This serves two main 
purposes: to provide a resource for other open source development 
efforts (such as Linux and BSD variants) to make their software 
available on Mac hardware and to provide source code to aid developers 
writing device drivers and other low-level technologies for Mac OS X."

That's not the traditional open source statement of "for the betterment 
of man."

I first tried to install darwin at an annoying failure, and instead 
went with FreeBSD.  The main reason I wanted darwin is because I use OS 
X.  But Apple's commitment to darwin seems mainly to be along the lines 
of "we want you to buy OS X instead of darwin, so here's a bare 
operating system we don't guarantee any of you can use."