Running over people is not why some said he had an NFL future. All that shows is strength and determination.
I thought he had a bright future because he is tall, strong, moves well, and throws accurately (at least when not injured or running for his life). To develop into a prototypical NFL passer, a Brady or Roethlisberger, requires time in a system to learn to read defenses and respond correctly. That is where Tommy never got a chance.
People are judging him unfairly. It's not much different than being critical of an injured freshman starter. No one develops as a QB sitting on the bench or playing a different position. That didn't help Michael Robinson develop into an NFL QB, and it certainly hasn't helped Stevens.