And that's how it should work. I also agree with Clip4. If the aircraft is in pieces, surrounding by cardboard boxes full of parts, and everything has a good coating of dirt, the lease should be terminated. If there's no work being done to return a plane to service over, say, a six month period, same.
Airport managers should have the right to inspect hangars every six months or so to monitor compliance with the rules.
Why are small airports dying? No aviation activity. But it cannot be argued that the driver of activity doesn't exist. There are many airports like McKinney and Aero Country, that have long waiting lists for the rental of a hangar.
If three fourths of rental hangars are being used to house derelicts or the operation of a plumbing business, there is no fuel being sold. The businesses on the airport, like FBOs, avionics shops, maintenance and repair providers, and training operations (from schools to individual CFIs) cannot survive if there aren't real airplanes with pilots that buy those services.
I'm sure many will loudly protest that my opinions are un-American overreach. But the use of rental hangars to store aircraft that will never fly again or to operate non-aviation activities penalize those like the OP, who needs a place to store his flyable aircraft. He will also provide revenue to support the airport and its businesses.