The main reason the mid-western lines were abandoned was because they lacked economic viability. For many of them, "operational" in the later years (some into the mid-1990s) consisted of a once or maybe twice a week short mixed. Whether the government of that era should have spent public money to assume them I will leave to others to argue. A lot of the communities that those line served, outside of Orangeville and Caledon and perhaps a few others closer to the Golden Horseshoe, have bare grown in the past few decades.
I won't engage on the details of each line, as frankly I'm inexpert on their various merits and drawbacks and what was or was not required to maintain them as a going concern at the time.
That said; in cases where the ROW was not preserved, I have very deep concern......
I just look at what R.C Harris built for Toronto..........
A huge viaduct across the Rosedale and Don Valley (in 2 parts) at a time when the Danforth was a dirt road; and on top of that built them with decks underneath that would one day allow for Line 2 subway service (on the larger one); at time when Toronto wouldn't see any subway service at all for another 35+ years.
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On top of which he built a Water Treatment Plant that now bares his name...........capable of serving 800,000 people when the City was barely 1/2 that size; and its still in service almost 90 years later.
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I don't see why any politician or bureaucrat should be held to a lesser standard. Think ahead, way ahead........
If infrastructure may be under-utilized for a decade or even five...............so be it............
That doesn't mean you operate what you don't need/can't justify.
ie. The Viaduct was built for a subway, but none operated until the time was right.
ie. The Water plant had capacity, but it didn't pump/treat water that wasn't needed.
