Is it just me or do a lot of the apps in the iTunes App Store, at least utility-oriented apps, end up with ratings of two and a half out five stars? It's almost as if that were the default rating for many. You might argue it's not that surprising ratings for a given title tend to average out somewhere in the middle. But why should they? Ratings for other media categories within iTunes like movies and music seem to drive more of a consensus around a given film, song or album. You're more likely to see average ratings of …