The people that get the angriest about astrology understand it the least. They think that you're supposed to tell who you are by looking at one thing, and that couldn't be farther from the truth.
In reality, it's a very complex equation with multiple variables that change over time. People don't understand that your chart reflects many different signs, and where the signs exist on your chart at certain times can describe aspects of your personality.
Having Aries as your sun sign means something different than having Aries as your moon sign. But they still contribute to a larger picture. And then on top of that, depending on if you live out of more negative or positive aspects of your personality can bring out different traits that might not have much to do with your sign at all.