Amtrak has indeed received a modest yearly subsidy since its creation. But I do not agree with the expectation that long-distance train service will be profitable ever in the US.
I feel that the primary value of passenger rail is that the US has a redundant form of transportation available to all. Airports and highways close occasionally, and Amtrak provides a backup method for people to travel.
If Amtrak is disbanded, there will never again be a national passenger rail network in the US. Like the interstate highway system, I believe that the federal government (not the states) should provide for Amtrak as a national service.
The issue of pensions for government workers is not limited to railroad retirees. Many government workers receive defined benefit payments which are becoming rare in the private sector. The argument here is that government workers are paid less than private sector equivalents during working years, and the pension is a form of deferred compensation.