Worst coolant I've ever seen

From all I have read, the most common issue with Dexcool is when it gets any air in the system. The OAT inhibitors allow all lot of rapid block corrosion in the presence of air (catalyzed by heat) that is prevented by silicate inhibitors (which are not used in Dexcool).

If Jeeps are having such issues with Dexcool, it may be that the Jeep cooling system design is such that there is more air in the system than in GM cars. Chrysler (with Jeeps) switched to HOAT coolants in 2002 or so, which has the silicates that give much better block protection in the presence of air in the cooling system. (The older green coolants have silicates too.)

It sounds like using Dexcool in such cooling systems that have some air in them is a problem guaranteed to happen, and investigation by GM showed low coolant was a consistent cause of rusty type contamination. S10's, perhaps like the one mentioned by BlueDream, had a known issue here addressed by an SB. See here:
http://www.imcool.com/articles/antifreeze-coolant/dexcool-johnbrunner.htm

I have been converting slowly to HOAT's like G05, which have the silicates to avoid the low coolant/air-in-the-coolant block corrosion issue with Dexcool. With the old Mopar systems with the open air gap in the top of the radiators that was the norm in non-overflow systems, there will always be some air in the cooling system so OAT's like Dexcool look like a bad choice there. So far, so good with the G05 for my car.

To the OP, I have to wonder if the Dexcool just got low or if perhaps there is a head gasket leak in that Wrangler. Any leak would not be good with Dexcool.