My 2 cents.
Landfills
-Landfills are anoxic therefore organic material does not biodegrade particularly well, if at all.
-Landfills in many parts of the country are filling up, hence the recycle and composting push. We have a composting bin that gets picked up, but its not that big, definitely not big enough for a deer.
Slob Hunters
-Not sure what this actually means, seems I hear it most with people dumping deer hides near the road. Not sure why that is bad actually? Because carrion eaters are attracted and therefore likely to be hit by cars? Anyway clearly a thing, people don't want you to do it.
-Probably not a lot of people are going to pack back in a deer or elk.
Given those realities seems like the most ethical/green thing to do is to leave any parts of the deer you don't want in the field. Let them be food for other critters.
I'm taken deer out whole, aged them, hoisted them into a tree in the field, packed them out bone-in, bone out... probably about everyway you can do it. I honestly think "the cleanest" method is to have help and to "rug" the animal and bone out as you go, though really it's all about paying attention. I've blown hair all over a deer I skinned while hanging in a barn... cutting the hair like a rooky.
Anyway that's my logic, anything I don't plan on eating or using or I'm not required by law to remove I leave.
@ajricketts sorry for the derail, nice adventure, jealous but also glad you got to have that experience with your dad!