bug#21746: 24.5; purpose of dired-keep-marker-copy?

["Roland Winkler" <winkler@gnu.org>]

On Sat Oct 24 2015 Drew Adams wrote:
> > > (FWIW, if you want to remove all marks you can use `C-x C-v',
> > 
> > M-DEL
> 
> Yes, I already mentioned that earlier.  Specifically `C-u M-DEL',
> if you want to remove all marks of any kind.

This thread has moved in a different direction from why I originally
submitted this bug report.  I know that there are various ways to
get rid of the C's when copying files in dired.  But nobody showed
why they are useful in the first place in some common usage scenario
justifying the current default.  Therefore I think that the default
of dired-keep-marker-copy should be changed to nil:

- The C's are irritating and inconsistent:

  The marks `*' and `D' indicate that an action _will be_ performed
  on certain files.  The C's indicate that an action _has been_
  performed.

- There is no future action associated with the C's (nor has anybody
  shown that this would be desirable)

Roland