I suppose I could have been more precise in my wording, and clarified that I see it as a solution to a piece of the puzzle. Indeed, you do word it better in saying it is a layer. I agree. It is a solution to facet of a problem which exists at a certain layer.

I don't quite know how my comment led you to believe that I think airgapping is a pancea which solves all the existing computer woes in the world.

I certainly don't think, and didn't intend to imply, that airgapping removes the risk from contractors or a reason to not keep up on patches. Again, I'm confused how you reached that conclusion based on my comment.