Frankly, I would hate to live my life being concerned as to who was about to enter each door, and afraid that someone would come up behind me and shoot me like Wild Bill.
If I were so worried about it I would not eat out. If we were to take statistics, how many times has a gunman entered a restaurant and shot someone? Yes it has happened, but if you consider the hours restaurants are open and serving and the number of people who eat there, I am convinced that the odds of getting shot are one in several millions. I am not going to spend any time worrying about such odds.
I am not going to be very concerned about such probabilities, and I would be concerned about my being paranoid if I worried about it.
Maybe Mafia dons have such a problem, but in my lifetime I have never known anyone who used a gun in SD except LEOs or military in combat.
I enjoy life and when I eat out I enjoy it. I may carry if legal, but I don't worry about where I sit from a danger standpoint. In NM so many restaurants have bars that I cannot legally carry anyway. I am not the least uncomfortable in those situations.
Just replying to the OP, and giving a different slant on the subject.
Regards,
Jerry