The business is apparently ran from their home. As such, they should not have to answer to you, me, nor the State as to how they conduct their business and who they do, or do not allow to enter their home.
And a business run out of a home is pretty personal.
I agree completely. This is another junk ruling that violates the wisdom of the historical allowances of the Mrs. Murphy's Boarding House exemption. Basically, exemption is a victory for common sense where the State declines to get involved in home based boarding businesses via aplying the Fair Housing Act.
http://www.huduser.org/periodicals/cityscpe/vol4num3/mathias.pdf
At the end of the day, the last thing the State needs to get involved in is business decisions involving who does, or does not have access to private homes.
It does not matter whether sexual orientation is, or is not immutable. The business is home based, as such the owner should have the ability to reject anybody for any reason- or for no stated reason.