I find dired--find-possibly-alternative-file a bit
confusing if dired-kill-when-opening-new-dired-buffer is set to t.

It's fine if the active window is the only window that shows that dired
buffer, but if there are multiple windows showing dired buffers, it's
likely that the user wanted to have those windows showing dired buffers.
If those buffers happen to show the same directory, opening another
directory with dired-find-file will kill the buffer, and change the
shown buffer in both windows.

Before dired-kill-when-opening-new-dired-buffer, to copy/move a file to
another directory, i could open a dired buffer, split the window, in
one of the windows (both showing the same dired buffer) navigate to
another directory and copy the file (with the dired-dwim-target).

In my personal configuration, i changed
dired--find-possibly-alternative-file to not kill the buffer if
it's shown in another window. I'm not shure if this would fit
every workflow, but for me it feels more logical.