Legit end-users, do not want brand confusion.
Not only do i get threatened with a lawsuit, but my customers will get confused whether they will go to this "big corporation" who owns the singular version, or go to your plural version domain. It is creating chaos, and that is not good for any "legit" business.
As a Domainer, you can still sell that domain. Because many end-users (especially the small-business types), do not really have any exposure on branding. So you can ditch that domain to a buyer, if you can and then run. But larger businesses who do brand research, will probably avoid it.