First, the photographer tried to take it to the Supreme Ct., not the gay couple.
Second, posting in another gay thread, eh? Your fascination continues.
Third, all the property rights excuses are completely identical to the rhetoric southern whites spouted during the 1950's-1960's trying to deny Civil Rights legislation. "You can't tell me what to do....private property! Property rights!" We see how that turned out, yet the same arguments are being made yet again to justify trying to discriminate, again.
Guess the next thing is to revive real estate segregation.....the practice that was codified into sales contracts amongst real estate agencies that restricted anyone other than a white from buying a home anywhere one wanted. Blacks, asians, etc., were only shown homes in certain areas, rarely in "white only" enclaves, even if they had the cash/credit to afford said home.
And when one speaks to "privately owned businesses", one is simply referring to the difference between a business owned by an individual vs. one with multiple investors, such as a corp. This does not exclude a "privately owned business" that serves the public from following law, despite the protestations of some.
You want a true "private business"? Start charging membership fees, then you can truly discriminate as to whom you serve. If you choose to serve the public, you serve all the public and cannot simply pick and choose from that pool your select customers.
Oh, and before you bring up the "No shirt, no shoes, no service" BS, sure that's a reasonable exclusion, but it's applied to every customer.