This was actually my immediate reaction - so AirBNB because of it's size is going to attract some racist hosts because their demographic is "anyone with a room"

This was actually my immediate reaction - so AirBNB because of it's size is going to attract some racist hosts because their demographic is "anyone with a room". If you create a site where the intended demographic is "anyone with a room that is pro-inclusivity", then surely you could create a community around people who self-select as not perpetuating racism/transphobia/general bigotry.