That's because people like myself buy the "higher than base trims" as you call them. I have a Limited, and enjoy and kindof need (high end job... and need a high end vehicle) all the bells and whistles. I'm also lucky enough to be able to afford it. But 80 or 90% of the time, I really should just be driving a regular old high end sadan (Caddy, Audi, BMW....) back and forth to work on regular streets and hwy's. Then the opther 10 or 20% of the time jump in a truck to carry stuff (fishing/boating gear, hunting, skiing...). But since I really don't have the space or want to waste the extra money to purcahse, maintain and store 2 vehicles for myself, I instead buy a high end truck that has an inside like an executives sadan, but has the utility and features of a 4x4 truck I can also use.
So for me, I the transfer case works just fine. I just got back from Vermont skiing last weekend, most of the 6 hour trip on dry roads, with a few icy or snowey patches thrown in when getting off the highway for a stop. Then when driving around killington, VT and in muddy/snowy/icy driveways and parkinglots and back roads, I had 4 Auto to use. At one point, we went up a very steep hill that was a pure sheet of ice and snow, so I popped it in 4 lock, worked perfect.
Am I rock climbing with the truck? no! am I mountain climing with the truck or whatever they do out west? No!
So RAM and the other companies probably know exactly what they are doing when they pair high end trucks (upper trim levels) with lower end t-cases. They are cattering to folks like me, which are by the way, the MAJORITY of their customers.
NO THANKS!! See my post above! My F150 required 3, or $10k of tranny's to be REPLACED in short order! I don't care if ther Tcase is GOLD plated, they can stuff their tcase up where the sun don't shine!