The machine in the garden usually implies some form of prosperity--and it matters little whether that belongs to the past, present, or future. The romanticism of the human intervention saves a natural landscape from drifting too far into the sublime. What is El Capitan without the scars of crampons?
The resurrection of old factory towns is a romantic pursuit. Those who indulge in it experience occasional victories, but at great cost. Cheaper to build a strip mall and a suburb where every house has an obligatory patch of chemically enhanced front lawn. The old factory towns decay better.