I'm guessing it was added due to a misunderstanding of how shell
quoting works. When you invoke
stow --ignore=".#.*" ...
the shell strips out the quotes before the Perl process ever sees them.
I can't imagine any sensible scenario in which you would need to invoke
stow --ignore='"foo"'
but if the user has a filename containing quotes at the beginning and
end, they can now choose to ignore it (prior to this patch, they couldn't).