Mainly, that Rodgers has the ability to kill the motion. To a lesser extent, you are implying the assumption that Rodgers knows two defenders will follow the motion, which is obviously ridiculous. In addition, we don't know if a Bronco was lined up incorrectly and would have moved regardless, especially if Rodgers has the option to bark out a 'kill motion' and had done so.
It is easy to critique a play knowing the outcome. Many other factors are at work, several of which we, as fans, will never know. We also need to remember that plays within a game are not independent events and showing