Using navigational view is difficult for browsing into deep hierarchies, for
example for landing into places scattered over the disk where one is working
(say: editing a website, browsing for music, browsing source code - all of these
would be very far away). One clutters one's desk with windows and it makes
spatial mode unpopular.
There are ways to mitigate this, which require some learning: using Ctrl-L and
typing the path, with tab acceleration possibly. This is very much non visual,
and not really a gui either.
Here is a suggestion for fixing this:
Use bookmarks. These should include folders containing recent files, some
recently browsed folders, and whatever the user drags and drops here as well. To
do it the spatial way, it would simply look like a folder, or rather as a list
of icons.