Well, if you want to take the word of a bunch of Frenchies who found my pics offensive, the reason why I hang them like that is to desecrate the game and cheapen the hunting experience for all. It's a long story, but that's the meat of it.
In reality, the reason I started hanging them like that is that I was taught that way. I was taught by my hunting buddy, while hunting in Kentucky, but he was from Alabama. I had no idea that this was considered "wrong" in many parts of the world until I started getting comments online. By then, I'd been hanging deer head up for twenty years.
I have since did a little bit of sleuthing and found out this is mostly a Southern thing. It makes sense. The guy I picked it up from hailed from Alabama. I have also heard it speculated that this has more to do with warm-climate tactics. It is very quick and efficient.
Instead of a gambrel, I use a 2 foot length of chain with an S-hook on the end. The hook goes around the chain like a noose and holds the neck tight. For about 80% of our deer kills, I can roll a truck right up to the carcass, lift it onto the bed and drive it back to the meat pole. From there, I use a block and tackle to hoist the deer out of the truck, and clean the deer. All the entrails fall into a gut bucket. From the shot to being on the way to the processor can be less than an hour.
I've done it all sorts of ways. Head-up, head-down, on the ground, etc. What I like about the head-up method is that all the viscera is being pulled down by gravity. For the most part it falls out on its own. All I have to do is help it along. It all ends up hanging by the esophagus and trachea at the end, and they're pulled taught. They're easy to cut at that point. On the other end, after I have everything dropped down into gut bucket, I lower the carcass. Once it's on the ground, I saw through the pelvis, guide the rectum through and then cut it off.
In regards as to why drive it back to camp before cleaning, I got a bunch of reasons. As I said, about 80% of the deer we kill are accessible by truck. The work goes much faster if you have all your tools, etc. right at hand. In most instances it is faster to take the deer to the tools than the tools to the deer. About 20% of the deer we kill don't get handled that way. The most common reason is that they're too big or they died at the bottom of a ravine or both. In that case, I've got everything I need packed and ready to go-- knives, saws, lights and rigging. I've gutted in the moonlight with nothing but a knife and a flashlight, enough times I can tell you it is much easier to gut at the pole under halogen work lights.
The keys here are time and temp. A normal morning kill is going to be at 40F. A normal afternoon kill will be at 50F. That gives me about a 2 hour window to get the carcass opened up. Most hunters would not think anything of letting a deer go an hour without being cleaned. Mine are usually being driven to the processor in an hour.
Back to the original point:
I didn't mean for this to become a head-up vs. head-down discussion. The point I was trying to make is that I did this whole head-up thing, because I was taught that way. I wasn't trying to make a statement. So much of what we find abhorrent in other people's hunting pictures are that way. As much as I find that guy's odd pose obnoxious, I'm not going to condemn him.