One of the reasons I find the dereliction of many grounded bodies so sad is that the railways of Britain were largely developed to move freight, yet the preservation movement seems to almost totally ignore this aspect of transport heritage, along with the pre-grouping wooden carriages. There are a number of honourable exceptions. (Knotty Coach Trust, Isle of Wight are a couple that spring to mind) At least some places have the stock "officially" awaiting restoration" and once gone, it is gone. Although if drawings are available, a replica is always possible.
Yet from the point of view of someone who rebuilds these things (at 12" to the foot) goods stock is easier and cheaper to rebuild than coaches, although their potential for use afterwards is rather limited, I agree.