Why can't pkg-plist list directories?

[Sam Lawrance]

Aside from the fact that the pkg_* tools don't currently support it, is
there a reason why we use @dirrm in packing lists rather than just
listing the directories?

eg.

share/blah/blah.h
@dirrm share/blah

as opposed to the hypothetical

share/blah/blah.h
share/blah

I'm looking at a new port that creates a number of empty directories,
and sets ownership on others.  Currently we have to use @exec or
pkg-install scripts to create empty dirs, and to set modes/permissions
on any directory.  To me, it makes sense to have them packaged similarly
to files.

I don't presume such a change wouldn't break stuff... just
[pw]ondering :)