I fail to see what those numbers show you.
If you take the same amount of cost for two flights, one lasting 1 hour and the other lasting 5 hours, of course your cost per hour will come down.
My guess is that even if you factor in more fuel for the longer flight and higher maintenance costs for the shorter flight (owing to more take offs and landings) the numbers for the shorter flight would be higher.
Also I've never read or heard anywhere that prices are calculated thus. As far as I know, Airlines try to make sure that their NETWORK is profitable, not each and every route (even though I'm sure they'd love it to be so).
A few weeks back I found a passenger receipt lying in the aisle. Routing was SFO-FRA-AMS-ARN. Price was USD 127,-! When I gave it back to the passenger, I asked whether that really was the price he paid, he smiled and said "good eh?". And we´re not talking low cost airline here. I'm sure we also had passengers on the same flight that paid considerably more for the same leg.
Usually the price range on a flight to, say L.A. varies from a few hundred Euros to more than 2000,-, depending on how far in advance you've made your booking, and how flexible that booking has to be.
So, even if you do your calculations for passengers on one flight in one class, you'll get wildly varying numbers. And again I fail to see what exactly that would show you.
And lastly, (and I'm sticking my head out now) Airlines don't exist just because they love to fly you around the world at minimum cost, they want your money. Probably all of it if they could get it.
It's up to you, to deceide whether you're going to give it to them (and me, as I'll be serving your meal).