Can’t a private independent entity decide on their own policy?
I think they will, it will become a cost factor for many like colmados or small restaurants.
They won't pay a doorman. They may ask if you come in and sit down but by then they won't want to turn away customers if they haven't sold much all day.
You can imagine how bad some businesses have suffered since Covid. To put more road blocks on their success is criminal.
This virus is not the bogeyman many paint
And if you think the vaccines work well and you have your two (or 3)- then just go about your business and don't poke your nose in others' health decisions.
I have mine but I don't care if others do, on a plane, on a train or on the plains.
The world needs less busy bodies