Basically, it was a giant, expensive garden railway Tralee UDC/KCC got tired of playing with. You could argue that things like playgrounds and greenways make no returns either but these appear to be appreciated by the public.
As far as I can see in online discourse, I see no great appetite among locals to do anything with the railway, apart from the occasional "won't someone do something with the railway/it's a disgrace, Joe" type comments every few months.
I would agree 5T would be better off reassembled, cosmetically restored, ideally in GSR era condition reflecting the Inchicore rebuildings, and put in covered and secure public display, whatever about economics, the likelihood of it leaving Kerry for Dromod would be somewhere between slim and none.