I think jackulas addressed this well, but I just wanted to add: it can be easy to be shocked that discrimination still happens if we don’t experience it ourselves, but that is part of the privilege of being in a man-woman relationship. We don’t have to worry if a host will accept us of we book with our opposite-sex partner, so we might wonder: shouldn’t every listing be gay-friendly? Why state it then? We might not know how important it is for LGBT folks to be reassured that we are going to welcome them. That is why I’ve been thinking about adding, “LGBT-friendly” to my listing. I live in a liberal city near the “gayborhood,” so I had assumed that all my guests would know I’d welcome them, but I’ve still been considering adding “LGBT-friendly” to my listing to be explicit to those travelers who might not know that I live in a gay-friendly city where you can expect hosts to be inclusive. And, as jackulas noted, even in a liberal city you can find those who are eager to discriminate. There are still gay-bashings (drunks beating up those they perceive as gay) in my city’s gay neighborhood, so we still have a long way to go, despite the notable progress that has been made over the last few years.
Now, I wonder: does AirBnB still let you type in your own keywords to searches? I haven’t been able to figure out how to search for custom keywords beyond AirBnB’s amenity check-boxes.