I have to disagree. If I was a baker, I would have no problem decorating a cake specifically for a same sex couple. I have attended such a wedding. However, if I did have a problem with it, I would want to have the right to not participate in that event in any respect.
The baker(s), florists, photographers etc. who did not want to work at a same sex wedding delivering and setting up the cake, flowers, taking the photos etc. may appear unreasonably homophobic to you and me, but it should nevertheless be their right if they have moral problems with it.
As that same baker I would refuse to decorate cupcakes with swaztikas for the KKK or other white supremacist meeting, I would refuse to provide a product that in any way depicts pornography or beastiality or polygamy or an anti-gay theme or an anti-Christian theme or a dog fight event or anything else that I might have moral problems with. And even though I am not so pro life as to think all abortion for ANY reason should be illegal, I would refuse to provide a product or work at an event that was in any way pro-abortion.
Just as the baker should be able to refuse to provide products for or work at an event that was pro-life, evangelical, a rodeo event, a Civil war re-enactment, or anything else he/she had a personal problem with.
At the same time the baker or whomever should sell the products he/she DOES normally have for sale to any one of those people mentioned and anybody else who walks into the bakery to buy something.
The difference is in providing the product/service you have for sale to all customers without prejudice and in being forced to participate in something for which you have objections.
Perhaps the baker could warn prospective customers before they even enter their shop. They could post a sign in their window stating:"Due to our abide nag faith in Jesus Christ who taught 'He without saying n shall cast the first stone', we reserve the right to refuse service to skeevy little faggots. God Bless You!'
Same sex wedding cakes are no more pornographic than heterosexual wedding cakes.
And wedding vendors are not wedding guests. Neither are they wedding participants. A baker would deliver and ass male a wedding no cake, but not even see the happy couple. They are working at the reception hall while the ceremony is taking place.
Wedding vendors are nevertheless participating in the event, are present at the event, and/or providing a product/service specifically for the event which is a form of participation.
And no, you should not have to come up with and post a list of every single conceivable concept, cause, activity, issue, etc. that he/she might have a moral problem with and would prefer not to or won't participate in no matter who the customer is. Provide the products and services you do want to offer to all without prejudice yes. But to not provide a product or service depicting something you do not want to provide should be anybody's right.
Many times I have called up a service or seller to ask if they did or offered whatever, and they simply told me no they don't. Just because they offer similar products or services to others does not mean I have any right for them to accommodate me.
If we truly believe in liberty and the right to one's own conscience, that has to apply to everything and not just those things with which we agree.