When a builder designs and constructs a home, they are essentially creating a work of art. They are using their creativity to shape the space and to create a home that is both functional and aesthetically pleasing. I suppose a General Contracting company with a religious owner can refuse to build a house for a client based on their religious beliefs.
You're mixing up client vs product.
There's nobody here saying they should be able to discriminate based on the client.
We are saying they should be free to refuse to build a satanic temple, but shouldn't be free to refuse to sell to satanists that want an ordinary house.