In theory, correct. In practice, almost certainly not. The law does not say "Religious defense always wins." It applies a balancing test. There are two parts to the test. First, in order for the business to claim the religious freedom defense, it must demonstrate that the law being applied presents a substantial burden on the practice of religion. This won't apply to most businesses, because most businesses (especially large one's) cannot realistically claim a religious identity. They would have to be closely held (like Hobby Lobby), or have some explicitly stated religious mission. Even if the business could be said to have a religious identity, it would have to be demonstrated that the law substantially burdens their practice of religion. I can think of no religion in which it violates a religious principle to serve a gay couple in a restaurant or to sell some commodity or good to someone who is gay.
But we're not done yet. Even if the law places a substantial burden on religion, the state can still demonstrate that the law is the least restrictive means of accomplishing a compelling governmental interest. This is known as strict scrutiny. Some commentators note that this level of scrutiny is "strict in theory; fatal in fact," but the worst of the parade of horribles brought out by critics would not get past this step in the analysis. Critics have warned that doctors or EMTs could refuse to treat gay patients. That's preposterous because such a law requiring doctors to treat patients would certainly pass this test.
Now, when it comes to photographers, bakers, florists, etc., at gay weddings, the law may protect them. But do we really want to be forcing people to support something they find wrong? If I go into a gay person's T-shirt shop and ask for 2,000 T-shirts saying "Homosexuality Is a Sin," do we want to force the shop owner to make those T-shirts? If I went to a photographer who refused to photograph my wedding because (in her eyes) my wedding would be a cult ritual, I would prefer to know that rather than have her forced to photograph a wedding she objects to, and therefore do a worse job because of it.
