A business owner should, and does, have the right to ban guns from their property. but it should end there.. Here in Indiana it is not a crime to go into a store that has a no guns sign.. If they find out you have it, and you do not leave then it is trespass..
On the other hand Businesses that benifit from the government , with land tax abaitments for example, should not be allowed to ban such things from being stored in cars..
it is a trade off.. If you want full control over your property you should pay full tax..
If you want a tax break then the government / people can limit what you can do with your property..
I agree with your position 100%. I can't think of a single instance when it would not be reasonalbe to apply it.