The two most used apps on my devices (iPhone, iPad, AppleTV) are MLB at Bat and NHL GameCenter. Both MLB and NHL are very clear to what their leagues' blackout restrictions are, yet there are several 1 star reviews for each app from people complaining the apps are worthless because a certain team is blacked out. It would only take 30 seconds of research to uncover the fact that if someone lives in Chicago both White Sox and Blackhawks games are going to be unavailable on their devices.
MLB and NHL are strong enough to overcome these nonsensical reviews but I'm sure a lot of smaller developers have been damaged by ignorant reviews. I agree with Peter Cohen that the entire review system needs to be completely revamped or eliminated.