The rules changed after RG3, Kaep, and Wilson had success using the read option. The QB is now fair game after they hand the ball off. This was a major reason for teams moving away from the read option. Also, I don't think he read option was ever meant to be a long term approach. I see the read option as QB training wheels. Its a useful tool for young QBs which allows them to produce while they develop into pocket passers.