Your reasoning is common sense, the same kind that ultimately led to the need for the federal government to remove discrimination by force in the South. If the law were meant to be restrictive to businesses that participate in marriage alone, it would be clear about this fact. To this law, there is no difference between a photographer refusing to participate in a homosexual marriage and a line cook insisting that his religion would consider squirting mustard on a hot dog for a transexual to be approval of their lifestyle and thus a sin. The law seems to protect the concept of "straights only" public businesses, so long as the proprietor asserts their devout beliefs makes associating with homosexuals sinful.

"Let the invisible hand correct this" doesn't work when a minority is the one being refused service, and is especially ineffective when it is pervasive in the community. "Democracy is three wolves and two sheep arguing over what is for dinner."

I don't really care to discuss this at length. Discrimination is wrong, more wrong than weakening the responsibilities of the owner of a public business to respect federal discrimination laws. A state does not have the power to weaken those federal discrimination laws, even if it is under the reasoning that so doing strengthens the practice of religion.

Insisting that this law is unrelated to hiring practices feels a bit obtuse. If we say a business owner's religious beliefs are so sacrosanct they should be allowed to discriminate against customers by age, race, gender, or sexual orientation, why then does it make any sense to assert they are required to hire people of those qualifications? How does it make sense that the owner of a bakery is exempt from baking cakes for homosexuals, but can be forced to pay wages to them? What if the religion considers the discriminated party unclean, and burdens the practitioner with cleansing rituals? It's not a slippery slope, it's a very short hop and we have a precedent-based legal system.

There's no way this law is intended to do anything but legally protect discrimination, and I do not believe there are any personal rights that justify it.