Perhaps that makes sense from a legal enforcement perspective, that is, it is not practical for the government to prosecute everyone in violation of anti-discrimination laws. But does it really matter from a moral perspective? Can I discriminate against you just because I am small rather than large? How many employes would I have to have before I can no longer discriminate against you and what would be the moral basis for choosing that number? Can I refuse you service at a restaurant, or refuse to rent you a room in a motel, or sell you a house, or let you use the bathroom because it violates my conscience to do so?

@Heraclitus It is precisely from a moral perspective that it makes sense to make distinctions between big businesses and mom & pop businesses. Freedom of religion and association are positive goods that society should strive to uphold whenever possible.

@doug6352 OK, but what is that "moral perspective", or standard, that regulates my conduct differently once I hire one too many employees? What exactly is a "mom and pop" business? A family business? Walmart is a family business that got big. At what point did their "moral perspective" change and forbid them from discriminating?
What are the limits on freedom of religion? Are there any? Don't forget that this baker couldn't point to an official creed that said that he couldn't decorate a cake for gay people. He just decided on his own that it was against his religion. Can I discriminate against people as much as I want as long as I do it under cover of my religion? Human sacrifice used to be a part of religion. Is that OK?

@Heraclitus And what is the difference between a 4 unit owner-occupied building that is exempt from discrimination statutes and a 5 unit building that is not? You draw a bright line and everyone know the rules and the problem goes away.

@doug6352 The difference is a legal one, not a moral one, and as previously mentioned, this was made simply from the standpoint of enforcement practically. If you are equating a legal standard of enforcement with morality, then your religious conscience will change with every such standard, every such change in standard, and every related judicial decision. So, in essence, you have no individual conscience.