In my world, it's to protect private property rights.
That way, when someone owns a restaurant and snivelers such as yourself enter, he would be free to ask you to leave so that other patrons could enjoy a whine-free dining-out experience.
That seems fair to me.
BWAHAHAHAHAHAHAHA!!!!!!!!!!!!!!!
I have actually encountered anti-smokers sitting in the smoking section and whining about the smoke - this after they indicated no proeference for their seating location.