I don't know about the economics of the high speed Acela thing, but Amtrak actually makes money in the northeastern corridor. They've got a bunch of long routes all the way out west that no one ever takes. They don't ditch those because their's always some Congressmen who won't vote for the bill if they dump the route to his state.

If they made Amtrak private, they would ditch the western routes and be making serious money.