Why does Apple provide the "Ignore ownership on this volume" setting? This seems like a total abuse to the Unix file system ownership principals.  The only reason I can think of that Apple may have implemented this is that non-technical users were probably fighting issues with ownership and Apple wanted a simple solution.  For the technical user (i.e. someone who understands Unix), I see no reason to ever enable this.  Am I missing something?
It's for read/write access on shared drives.
For example, if you have a shared USB drive the permissions will most likely not match your particular credentials.  For you to read/write to that drive, Apple gives you this functionality.
Additionally, given that you must be an Admin to enable/disable this, it doesn't exactly &quot;abuse&quot; the UNIX file system ownership principals.