BadgeBunny is right that cops don't have a whole lot of say in which calls they get to respond to. However, they do have a lot of choice in how they handle the situation once they are called, and it is part of their responsibility to address any concerns as aggressively as possible WITHIN THE LAW. Obviously it is part of their responsibilities to know the law and the legal limits on their own choice of action. Certainly it would not be good police work to address a legitimately concerned citizen's call about a man with a gun by just telling the citizen that open carry is legal and to buzz off... if a call goes out, the cop needs to show up, locate the subject of the call, and make consensual contact to adequately address the situation. None of this requires any sort of suspicion of wrongdoing. In addition, a cop would be completely within his rights, as would any member of the public, to tell the subject exactly what he thinks of his behavior, and even to lecture him about how not all legal behavior is smart behavior. The process of making consensual contact, and the conversations that ensue, frequently give rise to reasonable suspicion and/or probable cause that a crime is being committed... in which case it is proper to detain the suspect, either for further investigation or for prosecution. But if there is no RS or PC present, no contact beyond consensual contact would be warranted. In the vast majority of cases, this sort of contact should give the cop a pretty good idea of whether the subject is actually a danger or not. And if there is no reason to suspect a crime is being committed, the cop can tell the concerned citizen that he checked into the situation, that the man is lawfully carrying a firearm, that he doesn't believe him to be a danger, and that there is nothing more he can legally do about the situation.
The problem with the bold part is that if while the officer is telling me is opinion, he also tells me I am not free to go or I am being detained. This means he is using color of law to lecture me about his opinion concerning what I am doing. With any normal citizen, I can walk a way but if an officer is doing this under color of law, I can not.