They could call another to do the ceremony since I do not believe that an individual person can be forced to do something against their will. The Cake baker and the photographer could have called in another to do the work for the business.
The customer could go down the street to another business that offers homosexual weddings, cakes, and photos. How difficult is that? I don’t go to a kosher deli and demand un kosher meat or cry about it after. I don’t go to a pharmacy and demand they sell me a medicine that they do not stock.
I think in at least one of those cases, the business owner did refer them to another business, but that wasn't good enough. It is not about getting just anyone to bake their cake, or take their pictures or perform their ceremony - they already know there are plenty of places and people for that. This is specifically about forcing CHRISTIANS to do so against their will, or be forced out of business.