The whole not enough fare-paying passengers to make up for the cost of building and setting up rail networks is always going to be the argument until someone has the guts to put it to the test. I think the US needs to do more research to better forecast passenger use, taking into account the possible effects of a good advertising campaign. People’s opinions can be changed and, once some start using it, word about the benefits gets round and then it’s from those with first-hand experience who can actually recommend (or advise against) using the railways. Big projects such as you mentioned will be a gamble but, if handled one at a time, the success or failure can be measured and proven. ATM, there’s too much speculation, with the bosses simply chickening out as a result.