Well they refused to accommodate anyone who wasn't married.
And only some people would be attempting to buy the MAP.
FWIW, I don't agree with the B&B couple. But I can see that there are discrepancies that make people feel that the rules don't apply to everyone.
Whether you agree or disagree is down to your own position, your own experience, your own beliefs, etc. - after all there are as many sides to a story as there are people telling it.
My best friend, who is gay, and I were talking about this last night and she said she didn't see what the problem is. The couple don't represent the views of the majority of people, they are a couple running and minding their own business and maybe they should be able to run it as they see fit.
It is distasteful to a lot of people but until they are out protesting in the streets, their personal and privately held beliefs are theirs. They weren't rude to the couple, just told them that they did not permit unmarried couples to stay in their b&b.