It's good for forward towing too -- makes those sharp turns easier. It would be great on tight trails; or in tight parking lots/parallel parking if you're not the sort to get your truck scratched off-road. It would also be great for plowing snow, yanking stumps, and pulling cars out of ditches, activities which can throw the truck in all different directions or need it maneuvered in weird ways. And then there's just having fun doing donuts in snowy parking lots...imagine how much more fun they could be!
You can select between 2ws, 4ws turning, and crab-steer modes.
With a little bit of hacking you could have controls for steering the rear independently, which could be useful at times, and could just be fun other times.
These days I mostly just commute or do basic towing/hauling, but when I used to do a lot more tight maneuvering on jobsites and trails I could have really made use of it.