It's completely opposite scenarios between removing someone that's disorderly and impacting their business and that business purposefully creating a situation that causes liability..
If you own a factory and require people to wear badge lanyards that don't have beak away safety's and someone gets pulled Into a machine, you're liable. If you own a scrap yard and post a sign that says no gloves and someone cuts their hand, you're liable. If you own a scuba diving business and you say no flippers and someone drowns because they didn't have flippers, you're liable. If you prohibit a person vetted by the state to carry a weapon for protection and then something happens, you're liable. Businesses should be allowed to post whatever sign they want. But if because of that sign someone can't protect themselves that business should be liable.