Noodle arm quarterbacks do exist, bad o-lines do exist. They just might even exist on the team you root for. That possibility exists.
There is nothing profound or virtuous about avoiding that and living with rose colored glasses. In fact it makes the fan base look juvenile. The possibility also exist that a fan might root for his team and its players while simultaneously living in reality about its/their potential...or god forbid speculate differently than other fans, and if one were to do so they shouldn't have their fandom questioned like is often done here.