Back in the olden days there were a set of methods by which wiring was installed that supplemented the code. Sometimes called "Standard Wiring Practice", verbal and physical instruction from an old hand who taught me to "put in a little something for the eye", i.e., care enough about your work to make it look well thought out. The extra conductor length makes for less strain on the lugs, allows for some settling of the conduit/backfill(as mentioned above) and gives slack to the Sparky who has to modify the situation 10 years later. It's called "good work" Perhaps the loops pictured are a tad tighter than the minimum bending radius but the individuals who write most of the rules never had callouses from attempting to fight 4/0 XHHW on a winter morning. If the lugs aren't the lay-in type, the loop is much easier to terminate than a short stub of wire a few inches out of the bushing. IMNSHO