Actually, my tree carcass serves a purpose and we buy from a farm, not a mass production site. My Dad has a six acre (however much that is in water, I have no idea) pond ... my dead tree along with about thirty others that we collect from people, go into the pond every year. If we didn't collect the trees for the pond, they'd be taken to the Botanical Gardens where the limbs are stripped for mulch and the trunks of the trees used to make benches that are used. It's pretty cool, actually.
So there is no landfill addition ... merely habitats for the fish he sells (actually makes pretty good money off of them) to lay their eggs and repopulate the pond, since its man made there are no natural habitats within the water. He'd have to get the trees somewhere, turns out Christmas trees are the perfect place. And the money I spend buying that tree goes to help a small, independent farm/nursery (which also happens to be where we buy our pumpkins at Halloween and other stuffs during the spring) and the family who has owned it for generations.
Trust me, my father was (is still, sort of, even with the long hair) a hippie ... my entire life was "waste not, want not". We contemplated a live tree, but where we live its just not feasible.