Agreed. I usually hate on Apple, and its terribly ancient utilities and gratuitous incompatibility with modern Linux utilities, motivated by hatred of the GPL license.

But in this case, I think what it's doing is… basically fine? "Tar should faithfully reproduce the semantics of the source filesystem" is a perfectly reasonable starting point.

Ideally there would be a documented way to turn off the Apple-specific metadata with Apple's own tar, though.

From tar(1):

     --no-mac-metadata
             (x mode only) Mac OS X specific.  Do not archive or extract ACLs
             and extended file attributes using copyfile(3) in AppleDouble
             format.  This is the reverse of --mac-metadata.  and the default
             behavior if tar is run as non-root in x mode.