But it does connect, and doesn't go to nowhere...

Rail runs on tight schedules and run from single point to single point, which leaves it un-utilized for long stretches between the train schedule. Trail is open full time for people looking to use it.

It's the same issue with the light rail over dedicated bus lanes or Bus Rapid Transit systems. Light rail is great until something disrupts the path from point to point. The buses allow for flexibility caused by disruptions.

I'm not sure why you're so dead caught on rail. It's pretty great for a lot of things, but there are plenty of other options and solutions that provide more flexibility and are less costly to achieve the ends. For a small spur like this I'd argue that it makes a lot more sense for it to be a pedestrian right-of-way rather than a rail.

It's not hard to find anecdotal evidence of people using the Three Rivers Heritage Trail, or other bike routes, to ride into town from the neighborhoods connected and adjacent, which would of course be a reduction in car dependency. The cool thing about trails is that they still exist and can be used in bad weather and there will of course be people that do use them, just like they do now.

And market forces are an indication of viability. As to whether the market forces should be the end all determination is a different discussion all together.

And do you have a link to the study you were talking about? Because it sounds like that should have a lot of input on the viability

I mean I think the big thing you're overlooking is that by providing more pedestrian/bike access you are reducing overall car dependency particularly by providing a new connection point over the rivers. Use of this trail doesn't have to be strictly to recreation / leisure. The neighborhoods adjacent, I would anticipate, will benefit in increased mobility and a reduction in car dependency.

Can you link to the study you mentioned? Ultimately, in my opinion, this rail route would not really be viable or useful for commuter or freight corridors, and that is demonstrated in the fact that they had dwindling traffic to the point of only servicing a freight yard and were willing to sell.