An hour reading, sleeping or just zoned out on a train is a lot less fatigue than an hour operating a car in stop-and-go traffic.
BART is loud, rattly, screechy, wobbly, and generally feels like it could fall apart any moment. I wonder if even third world countries are able to produce trains that bad. But in developed parts of the world, trains are quiet and clean and run smoothly.
In general when Americans say they don't like public transit, they mean they don't like American public transit, because it is so badly done in America.
The proposal here isn't to do public transit better, though. It's to get more people to use the existing, shitty public transit by pricing them out of driving.