I read the article and I don't think the author makes his point at all. To keep my comment short, I will give one example of what I see as the usual double-standard :"But more importantly, the refusal of service to gay couples is itself an arbitrary act. It is an act of domination – just like refusal of service to black or Jewish people or inter-racial couples. "
So, isn't it an act of domination when a photographer or baker, etc., is now forced to provide their services for a same sex wedding by the government? Refusing to provide your services for a same sex wedding is not even close to simply refusing to serve those same persons in the usual day to day dealings in life.
And why is it just a problem of people drawing lines only from a religious standpoint? Plenty of people have refused to serve certain people or groups for political reasons and no one says anything. But refuse on religious grounds and people get sued. This is flat out wrong.