Whether its real call for violence or not, its indicates an attitude problem with the owner. And attitude is everything in hospitality - it informs everything: the staff you hire, the ingredients you procure, how kind you are to customers that make a mistake, or disagree with you ... This guys attitude is Not that of a hospitable restauranteur.
I see the problem with GG in restaurants. I support the ban. After all, its for the benefit of the OTHER patrons in the place. But I still prefer not to eat at venues where attitudes like this flow from the top down.
Feel free to disagree - just remember its your ass kicking he may call for tomorrow because of a bad tip or Yelp review.