Maybe it's just the conspiracy theorist inside me, but I think it's absolutely intentional that the DTE is not completely accurate. Can you imagine the complaints Jeep would get if the DTE clicked over to 0 miles to empty and the Jeep just stopped because it ran out of gas?
I also think it's gotta be intentional that gas gauges move really slowly for the first 1/4 to 1/2 tank, then the needle drops like a rock towards empty. Gives the initial impression of good gas mileage, then scares you into stopping for gas before the vehicle actually runs out of gas. I've owned 9 vehicles from different manufacturers and countries, and 8 of them behaved like that. The only vehicle I had that still registered gas in the tank when the tank was actually empty was my first car...a 69 VW Bug, and the gas gauge on that was seriously faulty. I learned the hard way that I needed to fill up before the gas gauge hit 1/4 tank.
2012 Wrangler Rubicon 2-door
2009 Aprilia Dorsoduro 750
2008 MV Agusta Brutale 910S