I think it's equally shitty if churches and parishioners are unable to practice their religion as they see fit because of this, but I think it's illogical to think it would change if we simply allow civil unions as equal to marriage or allow same-sex marriage.
I mean, the Westboro Baptist Church is still tax-exempt and most certainly engages in hate speech against the military and gays, and they're still a-ok and actually get police protection.
I see no logical expectation of erosion of First Amendment protections on people's rights. In fact, making a law to respect and support Christianity specifically, imo, would be an equal violation of the First Amendment restriction on Congress, and through incorporation, the States.
Who would have thought a photographer would be sued because they refuse to do something that violates their beliefs? Just saying we are on a downward slope.