Why isn't the nationalization of America's railroads a bigger movement?

One push I don't see as much among Americans is nationalizing the railroads, seizing them from train company magnates and putting them under government control. Railway companies like BNSF and Union Pacific shouldn't be trusted anymore. Not only do they actively hinder regional and commuter rail, but they actively refuse to fund maintenance and upkeep on the rails they own that passenger rail uses in order to make a buck.

Nationalization could not only prioritize passenger rail over cargo trains, but also make the rails easier to finance and upkeep.

I live in Los Angeles. Here, the Metrolink service is so utterly unreliable and atrocious, with virtually nonexistent headways and service. The reason for this can largely be attributed to the rails Metrolink uses being mostly owned by Union Pacific or BNSF, and they actively hinder electrification.