Regardless of whether you love, hate, or don't care about the current diner/lounge arrangement, you have GOT to see the inefficiency of it! Dining cars are being hauled around empty for LONG parts of the trip. Between meal times, and of course late at night, you'll find only the conductor/assistant sitting in there. Lounge cars with attendant MIGHT break even for labor (though I doubt it), but they certainly contribute nothing to the train's bottom line. And that says nothing of the fuel, and much more importantly, the maintenance of the extra car that is revenue neutral at best. The inspections, the heavy repairs, the cleaning . . . that's where I think the money is.
Now, like diner lite, I'm not totally sold on Amtrak's method of changing this, yet. Some good (though not conclusive) arguments have been presented to me that diner lite loses more in revenue than it gains in reduced labor expenses. If true, obviously it's a bad idea. You could certainly make the argument that one dining/lounge car will not have capacity for enough passengers to eat. You could also argue that there may have been better ways of dealing with this (charge a "cover" to get in the lounge car and try to make it a revenue-producing, upscale experience, for example). I have no problem arguing with the methods, but blanket "the-sky-is-falling (again)" statements aren't going to help preserve long distance passenger rail.