Eating kangaroo is better for the environment for a number of reasons:
Kangaroos damage the soil less than hoofed animals, such as sheep and cattle, because they have soft feet.
Kangaroos can travel long distances to find food and therefore do not damage an area by overgrazing it, if left free to roam elsewhere.
Kangaroos are naturally adapted to the Australian environment and can control their own fertility to match their food supply.
They are too wild, and good at getting through fences, to be easily farmed, so they will probably continue to be very fine wild game.
Kangaroos are a commercial alternative to sheep and cattle already:
They are hunted not farmed, so the labour costs are lower.
They are already exported for human consumption, because there is a niche market for them. So by definition they are commercially viable.
The main impediment is that many people overseas think they are cuddly pets, and some Australians think it is low status food, or object to cruelty in the hunting practices.
You can buy kangaroo steaks in my local IGA supermarket. (I do not like the sausages)
Kangaroo meat is much leaner than lamb or beef, with very little cholesterol, and therefore better for your health.
Cooking tip:
I used to fry K meat in a pan with olive oil. This leaves a liquid, whose taste I dislike. My daughter's partner has it figured out: roast it lightly on a barbecue. Delicious.
I'm glad to see someone sensible here regarding eating kangaroo. There's a number of figures, including people like Tim Flannery, who support the idea of sustainable, humane kangaroo consumption in this country. While I may be (mostly) vegetarian, I don't see any time soon when the majority of Australians could be weaned off their meat, if you're going to eat it then at least eat an animal that does least harm to the environment. On which note, has anyone else out there noticed that the ACT Government's recent proposal to cull kangaroos rejected harvesting the meat in favour of burying instead? The prejudice against kangaroo (which btw if anyone out there is a pet owner you can buy it at the major supermarkets as high end cat/dog food you have to read the fine print to know it's kangaroo) is so strong in this country that no one will touch a perfectly good meat and prefer to let it rot rather than find a productive use for either human or animal consumption. The ACT government so lacks creativity that it simply labelled it 'uneconomic' to do anything but bury the carcasses.