There are easy ways for AirBnB, and other companies, to find out if there is discrimination amongst the people they allow to provide services through them, as your booking experience vs your friend’s just showed.

Why not use their resources to see if that is what is going on and promote a non-discriminatory booking site? If users don’t want to adhere to those parameters, they don’t have to use that site. I think AirBnB makes enough to let such people take their “business” elsewhere.