runningart2004, you're not taking account of how, first, you need to gradually increase mileage, especially for those who haven't run before, and second, that when you increase mileage you need to do preventive and muscle-strengthening exercises to ameliorate the inevitable imbalances and strains.
I have averaged over 4,000 miles per year for the past eight or nine years now through these methods (actually, just the second: I jump right back into 10-14 miles per day after taking time off at the end of seasons) after getting injured every two weeks in high school and college on light mileage.