One reason so much wild game tastes like crap is people just don't know how to handle their animal after they bring it down. There really is a lot to know. I lived in Eugene, Oregon for awhile and one of my friends there worked for the US Forrest Service and was a big time hunter. He knew his stuff and every time I ate at his house it was wild game and it tasted fabulous. As a kid I really didn't like venison and elk. I loved jerky but hated the steaks. This guy's steaks were so much better. Then fall rolled around and we did a lot of hunting and that is where I learned how to properly dress down an animal and how to prep and butcher an animal. That was the difference. Get the guts out ASAP and carefully and then let the meat age in the proper humidity and temperature. That's why aged beef is so much more expensive and so much better.
Guts just put bad things into the body. All the bacteria wreaks havoc quickly.