In my experience Amtrak sleepers are almost always a premium over flying. Amtrak coach can be cheaper, especially near the departure date, but not by enough to make sitting in a chair surrounded by noisy folks who are prevented from taking a shower for 1-3 days anywhere near worth it.
You're correct insofar as the Des Moines situation is an extreme outlier (the numbers look a bit better at the moment...oh, I only need a
nine month advance purchase so that a cattle car airline ticket will be cheaper than a sleeping car with included meals...and even now, coach is still on par or cheaper from what I can tell). However, if you restored through service in Roanoke (ha!), I think you'd find a similar story. There are a couple of other "bad" air markets like that. Not many, but a couple.
Sorry for my explosive sarcasm...here's what I've come to the conclusion of: I will pay for decent service, I will pay for decent comfort. Witness the Acela, witness springing for a roomette on the NEC. Given the choice of it, there are plenty of routes that I would spring for a mid-bucket roomette on. NPN-NYP is one that jumps to mind (considering that I've done this RVR-NYP multiple times). I consider that to be service and comfort. "Service and comfort" is the operative phrasing here, and that phrasing being a good descriptor of what I feel I (generally) get with Amtrak.
Though the experience varies, the problem with the airlines collectively (and I say this without intending to malign those that do their best on the service front, though I
do blanket them all with blame for not speaking up on the TSA...it may be a logical decision, but that does
not mean I won't blame them for it) is that with the whole flying experience, the feeling I have is that I can choose how much I pay to be treated like I don't matter and run through a security theater that would be too expensive if it were free. At that point, yes, I will search out the cheapest cost for traveling...because if I'm going to be treated like crap, I may as well spend as little doing so as possible.
Of course, part of the problem with flying these days is that I suspect that comfort there has fallen victim to a tragedy of the commons: The guy willing to spring for an intermediate-class ticket (be it BC, E+, or something else) not infrequently has to throw out a
lot more to cross-subsidize the guy in coach who got a bottom-dollar ticket. I
am legitimately left wondering if we wouldn't be better off paying full fare for the briefcase...
...and then I remember Spirit Airlines wanting to, at one point, charge a fee for carry-on luggage. Oops.
Anyhow...enough with the rambling, I've said enough. If I'm offered a decent product, I'll go for it. Amtrak does, the airlines do not, and therefore my money and my time go to Amtrak. I have a good time and I enjoy
getting to where I'm going. That counts for a lot. And hey, sometimes it even
does come in cheaper than the relevant airfare.