Australia has become the leading source of US-purchased lamb because it's cheaper than most domestic lamb. Raising sheep isn't as profitable as cattle ranching and as even cattle ranchers are having financial issues, supply is down and therefore prices go up - capitalism in action.
'Gaminess' comes from two factors: the fat and the age of the animal.
In our household we personally enjoy lamb, goat, and also most offal. FYI, during WWII when the Nazis occupied Paris, cats were served on menus as "alley rabbit".
Being picky about your food is a First World problem, and I'm happy we are all able to indulge in it. There are a lot of people in this world and even in this country who DON'T.