Years ago I used to work on a trail crew and we did this over campfires on a fairly regular basis. We actually had a pretty nice set up with campfire cooking tools, so it was really done for the effect more than out of necessity. The big advantage of cooking with a shovel is that you let it sit in the fire for awhile and let the shovel get screaming red hot. This gives you an incredible sear on the meat. There are loads of other ways to replicate this effect, but I think the sear is the main benefit for the flavor, and the presentation is great.
True enough. The only ways I've gotten as good a sear as a screaming-hot shovel is either to hit it with my 500,000 BTU weed torch, or to cook it directly over a lit chinmey of charcoal.