As far as I know, UP shreholders don't subsidize any passenger fantasies, even the steam program. I believe it is considered a marketing expense, just like the "Great Big Rollin' Railroad..." ads that used to show on TV all the time. The people who purchase UP services would be a more apt "susidizer" than the shareholders, who, if they don't like UP expensing their marketing operations, can sell their UP stock and buy, say, NS stock.

If by "passenger fantasies" you mean the Starlights, Sunsets and Capitol Corridors, they rent UP facilities and have contractural incentives for the railroad(s) to give them priority handling and earn incentive fees for on-time performance. The taxpayers and, to some extent, the ticket buyers "subsidize" those passenger fantasies.

If we want an Amtrak train to run between LA and Las Vegas, and even on to Salt Lake, Amtrak would first have to "subsidize" train equipment sets and then contract of terms favorable enough to UP to incentivize them to accept any inefficiency the additional traffic would cause to their freight operations. I think it's up to Amtrak (a gummint corporation noted primarily for their "boldness") to get this ball rolling.