No, it's parking lot.
Who owns it?
It's the workplace, otherwise, why would you be bitching about it?
coming from a non-gun owning society i've read the thread with interest.
it seem to me that a change of venue would help this argument.
say i know you from work, i invite you over for dinner at my house on a sunday afternoon. you drive up towards my house and see a sign on my fence that says "no firearms on my property whatsoever" (i'm the owner of the property, its my choice) my property is my house, my garden and my driveway and it has clear boundries.
if you still wish to come to dinner you should park in the street and leave your firearm in the car, if you park on my driveway and leave your weapon in your car you are breaking my property rights to say who comes on my property and what they may bring with them. if you come into my house with a concealed firearm against my express wishes you are crapping on the most dearly-held of your beliefs - that of self defence.
so in that example it appears absolute, either park in the street and leave your firearm in the car - or drive to McDonalds.
so why is the employers parking-lot any different to my driveway? - its his property and he has chosen to make it flat with painted lines on it, that doesn't dilute its 'legitimacy' as property just because it doesn't have four walls and a roof.
property is property, my rights to decide what goes on there begin where my property begings, if i own the parking lot or driveway you may decide not to visit it because of my rules on firearms or on my prices, but they are my rules, if you don't like them, go somewhere else.