Funny how we pick and choose rights. I figure if it's their right to decide. If you don't like it don't go inside!!
Of course we pick and choose rights. How else do we know which ones we have? A corporation is not an individual and should not be treated as such. They do need some rights, but they do not need to be treated as individuals under the law. IMO the supreme court case in the 1880's (Santa Clara County v. Southern Pacific Railroad) that upheld corporate personhood to a new level was a bad decision. An actual person can gather only so much influence, because people have expiration dates and physical needs (sleep, poop, eat, ride motorcycles) and a corporation has neither. How much influence and money and power could you appropriate if you never had to do anything other than make money, and as long as you continued to make money, you could live forever?
Further, if the corporation knows that the area has a history of crime (and they know, they always know) they should provide adequate security to their employees, should they choose to strip an employee of his/her right to self-defense. If they don't, they should be legally liable for injuries and deaths resulting from such a poor policy.
Look, it's not like you are going to offend the corporation's religious or ethical sensibilities by carrying a weapon. What you offend is their fear of lawsuits. If the inside of a Walgreen's was treated as the public space it is, Walgreen's couldn't get sued for firearms incidents. Nobody sues the city because that's where they were when they got assaulted.