Massachusetts actually found a much better and more viable service from Boston South Station to Cape Cod by rail too. it just happens not to involve Amtrak.
Pennsylvania's fundamental problem is that the western half of the state really does not care much for trains of any sort
This is not really accurate.
Pittsburgh and its surroundings are clearly pretty supportive of passenger trains. The trouble is "Pennsyltucky" between Pittsburgh and Harrisburg.
The only place in between where a strong positive interest in passenger trains has been evinced is State College, which is why I strongly believe that Harrisburg-State College should be the next priority for "Keystone West". It changes the political dynamics.