There is no way to turn off displaying of ls-switches on modeline when
in dired-mode.

By default in certain configuration, dired display ls-switches on
modeline. In case those switches are a long list, for example:

"-lA --si --time-style long-iso --group-directories-first"

then everything else on modeline gets pushed far to the right which is
not very usable. In general I don't have much use of seing ls-switches
on modeline and would like to be able to turn them off. As of current it
does not seem possible since it is hard-coded in function
`dired-sort-set-mode-line' in dired.el.

I suggest, as small improvement, to introduce a user option to turn off
or on displaying of ls-switches on modeline. As a suggestion I have
attached small hack to dired.el as tested on my copy of Emacs, but you
might wish to rewrite it. Drew had some other suggestions.