It is legal. What do you expect with an epidemic of mass killings? What do you expect private businesses to do? Their shoppers want to feel safe and this is their answer, right or wrong. The voters will not put up with doing nothing about the mass killings. Politicians who do nothing will go down in defeat. It’s the new reality.
Eventually the insurance companies will determine that “gun free” policies are unsustainable.
They will make them unaffordable and then uninsurable.
There is no “epidemic”. Stop believing the lies the media trots out.