We as gun owners and carriers have to decide how far we are willing to go to not support anti gun companies or individuals.
It sounds good on paper but in reality it would lead to a pretty boring, antisocial life not to mention a very limited employment market. Here is an older list so there is probably more now. Generally speaking businesses do not care if we tell them we will not be back since they do not allow firearms we are the minority in this situation.
Anti-gun Companies, Organizations, Media And Celebrities - Gun Owners Of America
If someone chose to go all out and not do business or support anti gun places you would not send your kids to school as most of not all administrator and teacher and educational organizations are anti gun. You could not seek medical treatment as again most MD and nurse's organizations are anti gun. You could not have a union job as they are anti also.
Movies and music would be out also as many artists and actors are against firearms. Sports would be limited as some professional athlete's do not approve of firearm ownership. Forget the AARP, PTA or whatever they are called now, and you would have to think twice about your religious preference as many governing bodies of churches are also anti gun.
People in general will support a cause as long as it does not effect their daily life to much. I don't know how many times I have heard someone say I will never shop at Walmart again but yet they are in the store two days later. It is the property owners right to say what comes onto or into their place of business as long as they do not discriminate against race, religion, handicap and so on. Carrying openly or concealed is not a category in any of these so we have to make our own choice as to where we go and spend our money.
One thing to keep in mind is that while we carry concealed and no one knows IF we ever had to use our weapon in one of these posted places we could be in a heap of trouble. Generally speaking one of the first questions asked as part of the question "What a reasonable and prudent person would do in the same situation" is "Were they legally there in the first place?". If the answer to that question is no most of the time anything that happened after that even if you save the day is a moot point.
In our crazy mixed up legal system things that should not happen do even with the best of intentions. Not long ago a restaurant employee was carrying against company policy and shot and killed an armed robber. He had the best of intentions and probably saved lives but he was terminated for his actions. Should the family of the deceased, unless a state law applies and prevents it, could sue the restaurant chain because the employee was "illegally" in regards to company policy, carrying a firearm that led to the death of the individual.
In regards to employers banning their employees from carrying there is something on the books called "The Law of Vicarious Liability" which states an employer could be held liable for acts committed by the employee. Same thing for parents could be held liable for actions of their children. This liability can even be extended to a vehicle owner who loans their vehicle to someone you are responsible for what they do just as if they were driving the car themselves.
I apologize for being long winded but there is a lot to consider in regards to this.