A lot of it is definitely history. My life long home state of New Jersey used to be quite the industrial powerhouse. Now it isn't, and we have problems, and I wonder about our future.
My small 1950's N.J. era industrial layouts take me back to what were happier, simpler times. Though, those times were kinda before me.
I have some in O scale, but it is easier for me to do actual industry in HO. I also have a collection of the Atlas O freight cars that had "New Jersey" actually painted on them as part of the company/industry name .... again illustrating what New Jersey used to be.
Happy Railroading