[sudosysgen]

A big part of why the US moves more by rail is simply because it moves more goods overland than in Europe.

Low latency freight for smaller, high value items is often done on passenger lines (or even passenger trains) because it doesn't put any scheduling pressure on passenger service.

As far as use of freight in Europe, the elephant in the room is that the EU uses a lot more sea freight than the US. Indeed, while the modal split for EU trucking is around 50%, it's around 70% in the US, and it thus seems clear that the real reason that there is less rail shipping within Europe is because there is much more competition from maritime shipping.