Running backs have a way of getting their shot at the next level regardless of their college careers. They are rarely drafted high and their careers are short. Also, good running skills are not really taught, but pass blocking is taught and is essential in the NFL.
Although it sounds defeatist, it isn't a bad sales pitch. Get a good education, preserve your health, and learn the skill you need at the next level. That's a much better offer than "carry the ball 600 times in college and get your name on the Doak Walker watch list before you go into used car sales."