Yo also have the "right" to dress as you wish but business's have dress codes. Show up naked or in a clown outfit and you'll get terminated.
You also have the "right" to speak as you like but use profanity or tell a customer to pound sand and you'll be terminated.
The difference is business's don't have the authority of law. If they could put you in jail for doing these things I'd agree with you. But all they can do is let you go because you don't have a right to that job.
Here's a hint: It doesn't.
In fact, having a number of armed employees around helps with over all security and is a freebee for the company.
So... that leaves people like you with your general dislike of guns and fear of not being able to Lord over your employees like a petty dictator.
"Go pound sand" indeed...