The US rail system carries a lot more cargo than in Europe. On the order of 3 times more freight per mile of track. It is an also much cheaper to send freight by rail in the US compared to Europe. Reconfiguring the US rail system to even slightly more passenger friendly would seriously lower the amount of freight that can be transported by rail, as well as raising the price, and most of that would end up on trucks.

The other aspect is how the rail infrastructure is financed in the US vs Europe. In the US the infrastructure is to a large extent funded by the freight companies themselves, and in return their needs get priority. Take away that incentive and they'll stop funding the rail infrastructure meaning that much of that cost will end up pack on either the local or federal government, with all that that entails.