I defend the owner.
Denying someone their rights because they are gay, black or whatever is wrong, but they have not been denied their rights. They have no right to stay in this woman's guest house, no one has. She is at liberty to decide who she takes under her roof. It is a wholly private matter between the individuals involved. She declined their business, and is thus out of pocket. That is her affair.
This is how the law always was and always should be, but such principles have been well trampled under foot by the zealots of secular tyranny, who have so soon forgotten what it's like to be on the wrong side of an oppressive, illiberal law.