Dave, our country has limited the rights of private property owners when they violate the rights of citizens. It was the claim years ago that a private property owner might discriminate in his or her store on the basis of race.
That went by the wayside. Now, I know there are some folks around who would argue that the property owner still in his business should be able to discriminate on the basis of race. But that is not acceptable.
I opine that discriminating on the basis of gun carrying is a similar violation based on our rights and thus should not be allowed.
Since they pay higher taxes - they should be able to afford to protect themselves.
Anyway, the Costcos here don't have that sign and I don't belong anyway - so what!!