Eating a common animal to save many endangered ones?

Why would they be willig to eat meat when it is the very same food source that they choose not to consume? Instead of asking if vegetarians would be willing to eat meat, why not ask the omnis to consume more kangaroo instead of beef and lamb/mutton?. Perhaps that would lessen the numbers in the "artificial" grazing herds (cattle and sheep)which in turn would lessen the size of grazing lands required that would/or might lead to less pressure on natural habitat. Cows and sheep are not native to Australia but I believe kangaroos are. If there is pessure on the land, it would be the vast cattle and sheep herds not the kangaroo. My own experience is that the more man interferes or tries to control nature, th more problems are likely to occure, if not suon, then in due time. But that's form from a purely conservation point of view, not economic. I would not know the impact of reducing the cattle and sheep herds will have on the Australian economy.