I have a recently developed theory (and by "recently" I mean just this moment) that the best and most universally loved fruits are all red. I mean, think about it for a minute. We all know people who detest bananas. We are ambivalent toward oranges most of the time. Green grapes amuse us for a while, but ultimately don't win the popularity contest. Red is where it's at.
I have no idea what use or purpose this theory has, but since when do theories have to be useful? Also I really wish I could add peaches to the list, but they're not red. They're peach.