To process, say a pig, out bush away from a coolroom would need a generator and a dedicated camp fridge (Large), then you need the space to carry it (bigger vehicle?)and once you have it on the ground the hunting for that day has stopped. If you've driven 10-12 hours to hunt for a weekend and thats your yearly trip then your not going to waste time in cutting up a pig carcuss. Also some pigs (up north) carry some nastie stuff and most will feed on carrion....so stuff that, I'll buy a leg of pork from the supermarket on the way home.

Hunting deer would be different as mostly your hunting for one animal, once decked the hunts over anyway.