The ONLY REASON why 250/2500 trucks are maxed out to 10,000 GVWR is because that is the max GVWR for the Class 2B that the 250/2500 are in so get the idea that a 250/2500 truck cannot handle more than 10,000 GVWR out of your head. This 10,000 GVWR limit is also what brings the payload of a 250/2500 truck down especially one with a diesel.
My Ram 2500 is identical to the 3500 SRW I'm every way except rear suspension. The Ram 3500 in my model year has a front GAWR of 6,000 lbs and a rear GAWR of 7,000 lbs. My 2500 has the exact same front GAWR of 6,000 lbs and a rear GAWR of 6,500 lbs. Hmmm, why is it that there is only a 500 lb difference in GAWR yet the same identical 3500 compared to mine has a GVWR and payload rating of almost 2,000 lbs more? Because the GVWR of the class that the 3500 is in maxes out at 14,000 lbs allowing it more room to have a greater GVWR while the Class 2B that the 2500s are in maxes out at 10,000 lbs. There is no other reason than this. In fact you can order a F250 with the camper package and it will give you the exact same rear suspension and GAWR as an F350, but it will still not raise your GVWR passed the 10,000 limit.
If at some point the DOT and EPA regulations changed to raise the Class 2B GVWR to 11,000 lbs max, I would bet anyone here that the diesel 250/2500 trucks GVWR would increase to 11,000 lbs overnight without changing a thing to the truck. This idea that 250/2500 trucks (especially diesels) are limited to 10,000 GVWR is a false one and so is thinking that they cannot handle anymore payload then they are rated for.