Are you saying businesses can't ask patrons to do certain things? That isn't true in all states. Businesses have wide latitude to require certain behaviors and protocols of business-users. For example, the Goodwill near my house bans people from dumping "trash" at their pick-up docks when they're closed and the police *will* come for that - even though it's entirely up to the Goodwill (and their cameras) to define "trash." There's no ordinance that distinguishes between "goodwill items" and "trash."
The local pier bans people from fishing on the first section of it (for fairly obvious reasons, but some people are kooks) and the police come for that. Pier is open, the "no fishing signs" were posted by a local group that volunteers to protect the pier. I think they'd like a local ordinance, and one may occur some day - but in the meantime, that part of the pier is governed by leases to businesses - who call the police if someone fishes in their "zone."
I've seen patrons asked to leave because their kids were screaming and all service stopped until kids were taken out and quieted. There is no ordinance, and I've never seen people fail to comply when confronted.
I've seen older people asked to leave (and denied service) due to loud cussing (ha, this is a small town where I hang out). There are no ordinances, but the business in question has one of those "We reserve the right to refuse service to anyone" signs. And in fact, LE has been quite prompt in arriving if the parties in question get louder or belligerent. I've gone on ride-alongs and watched officers deal with such matters. I've also interviewed lots of police and keep an eye on many different police blotters (mostly in CA, but in other states as well).
There's a guy who is mentally ill and homeless (in California, neither of those things is a crime - and in fact, homeless people can no longer be asked to leave public property where I live - I think that's statewide). The police come quickly when this guy gets aggro and starts shouting. Shouting isn't illegal, but the police are trained to "assist" such people to seek treatment and do offer to give this guy his trip to the county mental health center's doorstep. They take a lot of time with him and are quite polite, but talk him into the backseat of a patrol car. People *can* be asked to leave private property and if it's the police who ask, you can be sure they don't need to post any signs first. They have no intention of charging this guy and do not tell him he's "disturbing the peace," they handle it differently due to his illness.
It's the business owners who call on this young man, because he walks up and down outside shouting incoherently and scares patrons. This is called "community policing" and it's simply how things are in the area where I live.