Wow this is a tough one for me. I feel for both parties.
I believe that the owners of the hotel, as a private business, have the right to refuse service to whom ever they please and have the right to conduct their private business in a way that is fitting to their religon.
But...........I also feel for the couple who were refused. Their relationship is IMHO as legitimate as a male/female one.
This is tough because I feel either way someones rights are being violated.