I maintain that nearly all of the time, it is a REGIONAL thing...
Nearly everyone north of the Mason Dixon lines guts them where they drop, or fairly close...
Many hunters in the south take them back home, to a camp, or to a processor for the gutting..
Hunting methods have a bearing on this.. In the more southern states, much hunting is done from established stands over agricultural areas where it is easy to drive up and throw an intact carcass into the truck, and take it somewhere to be processed..
Up north, we usually have to drag the critter off the top of a mountainous ridge, or out of a God forsaken hollow, and often getting a vehicle to it is not an option..In that case, lighter is better.. Why drag the guts..??..