We already have these rights of way settled. That is all the more reason that should not be abandoned.

It is typical to run minimal service to maintain the route, until service can be improved. China's passenger rail in rural areas looked downright dysfunctional 25 years ago, until it was upgraded, now it is the best in the world.

I think it is perfectly fine to run empty trains to the middle of nowhere.

NYC runs excessive service to neighborhoods that don't need it. There are four different lines to Coney Island that are nearly empty by the time they reach their destination, even during rush hour. They should not be abandoned though, because those neighborhoods have the capacity to grow. Neighborhoods that were lower traffic 20 years ago have only improved because of subway access, and are now reaching capacity limits. If we keep pruning parts of the network that are under-performing, we will be left with nothing.

I don't think that characterizing mass transit networks as unidirectional money sinks is correct. Cost goes in the other direction as well; if you invest more, then they expand and more people use them, and then they become more efficient to operate.

Eventually, populations align themselves around well developed public transit, but that can take decades. We just spent decades re-aligning the population around government subsidized highways and air travel, that's all.