For me its the History and the camaraderie. Nothing like 40 shooters at a match throwing serious HEAVY METAL down Range at one time. God help anyone on the receiving end of that!They aren't making any more of them.
Limited edition
Highly collectable.
Great piece of history the is shootable
General George S. Patton called it "the greatest battle implement ever devised
Great investment
It is the granddaddy of modern assault rifles and drives liberal crazy.
Many, many more reasons I'm sure.