Losing permissions is one thing. Annoying, mostly.
However, actual losing file data during such a copy is
nothing short of a disaster, IMHO.
In my opinion we shouldn't merge file-as-a-directory
semantics into the kernel until we figure out how to
fix the backup/restore problem and keep standard unix
utilities work.
--
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan