Back when steam engines were being donated for display a steam engine was on par with the old cannon in the town square. For those who worked to get it donated is was a memorial to the past. To the general public it was something for kids to play on. By the time diesels were being retired cities viewed a locomotive sitting in a park as a liability and a maintenance headache. Cities with steam engines had fenced them off and in many cases had let them become an eyesore.

I'll bet that any discussions on preserving a diesel would have had the naysayers pointing out rusting steam engines and a waste of park space as a reason not to do it.

A positive outcome of cities looking to get rid of their locomotives is that it helped the rise of preservation groups in the late '80's and '90's. The only hope for diesels now are the groups that grew up around a steam engine.