As a side note, I don't think passenger rail is truly profitable in any country, atleast not when you consider the costs of actually building the rail needed.
But in europe and other places where passenger rail is popular, the government supports its use in various ways because for the community as whole, rail is cheaper than cars. Its just very difficult for "railroad service providers" (better word for that, please?) to actually capitalize on the full service provided. The service is so much more than providing trips to customers, it has much more to do with shaping the city into something cheaper and more efficient.
With that said, I don't see what amtraks profitability has to do with anything. It's government owned, and the advantage of that is that it doesn't HAVE to make a profit. Sure, the people working at amtrak should obviously strive for profit, but I don't see why the profitability of amtrak should dictate when to expand passenger rail in America.