I argued this point on rr.net years ago, but the Port Jervis line in NY runs to a pathetic excuse for a city of less than 9k people. It runs through a ton of farmland, and no longer goes through the small towns it serves: instead skirting them on the old freight bypass forcing most of its ridership to drive 5-10 miles to the stations. The trip time is abysmal, something like two hours, and you have to either transfer at Secaucus Junction or take Path from Hoboken to get into Manhattan. It also gets the worst of the worst equipment from both the Metro North and NJT pool, always single levels, sometimes without a single bathroom on the train. The traps are manual and you have to basically figure out what car to be on to get off at your stop because most of the time they only open one door.
Even with all that working against it, the ridership got all the stations overhauled with fare vending machines, heated shelters, brand new parking lots and platforms within the last 15 years or so. Irene completely destroyed a few miles of the line near Harriman, closing the line for months. They rebuilt it amongst rumors of abandonment. Its also up for a complete signal overhaul. People ride this line despite everything saying it should have been abandoned 50 years ago.
My point is that commuter rail to Fall River and New Bedford is a great idea. It should have happened years ago.
The current iteration of South Coast Rail however, is a terrible project. It has more bloat than a beached whale. It is the horrid mutation of a science experiment gone wrong, and needs to be destroyed immediately. Lessons can be learned, but it needs a complete reboot.
What we need is for someone to get people riled up about this. Yes, FR/NB deserve commuter rail. But they do not deserve a premiere service right off the bat, just as a teenager who just got his permit does not deserve a brand new BMW, but the family station wagon. They get one stop each, as barebones as possible. They get whatever equipment the T can spare, and a matching schedule. Then when people actually ride it, they can start expanding and adding stations. Also, someone needs to get RI on board to get the FR branch down into Newport. I imagine that would get a substantial ridership boost, and also start a conversation about figuring out how to reconstruct the link between Fall River and Providence.
The only part I'm on the fence about is the all electric requirement. I think these are horrible branches for electric service, but it would force the T to buy an electric fleet, as well as build out Readville into a real maintenance facility. This would be amazing for the NEC, as well as all the issues identified from not having Readville built out.