Not to open a can-of-worms... but how does the Amtrak insurance thing factor into the entire operating on Class I side of the conversation? I have heard it tossed around a few times, but no explanation of how it got to this.
Example: PRR 1223 and 7002 ran over Amtrak to Philadelphia in the late 80s? What changed? Was it just CEO preferences as mentioned previously or bigger factors?
As far as I know, those Strasburg trips, along with similar Blue Mountain & Reading trips and later 765 trips in 1988, were under Conrail, not Amtrak.
The insurance required by the Class 1s in the 1980s was somewhat affordable. Rich or Jack can certainly give better numbers, but it was somewhat in the range of a $30-50M policy by the late 80s. You could also amortize it over the entire season, and when you're running 20 or so mainline trips a year, it was doable.
By the 1990s, the required insurance to run on a Class 1 was somewhere in the $300M range. That was basically unaffordable, especially since they weren't going to approve enough trips to spread the cost out. Nowadays, it's over $500M.
The only way to get around that was to run under Amtrak's own insurance. It involved jumping through more hoops as now Amtrak was being involved in the operation of the train. More recently, Amtrak said we just don't want to do this any more. Thus being the situation we find ourselves in today.
With NS subsidizing, or at least partially subsidizing, the insurance during the 21st Century Steam Program, you could have excursions again...and Amtrak wasn't involved at all. That option is gone now.