I would believe that the initial ratings are based off of the previous years efforts when the ships.
It's not unrealstic to have unbiased fans of specific teams notice some "wrong" ratings. I would never expect the madden crew to get every single person on every single squad correct. But if people are able to intelligently make a case for a rating they believe could be higher or lower, why is it a problem? The problem is that people voice their opinions without any tact or reason.