I doubt this lens is old enough to have the problem but not using a lens--just displaying it on a camera for years--is one of the worst things you can do to it. I have a few old Nikkor lenses I used professionally that I left boxed up for 4-5 years after I quit using them. They are unusable because the lube has dried out and the focus rings are nearly frozen solid. Before I stored them, I had them overhauled by Nikon Professional Services but that didn't help when they didn't get exercised regularly.
I agree that equipment should be used. I've enjoyed depreciating the value of every piece of photo gear I've ever bought.