This song is about a friend of the Hayleys. This friend judges her out of ignorance. Most people walk around saying they don't like this or that. And they blame the thing they don't like, they call it bad. But that's just their opinion, and causes a big wall between people sometimes.
For instance: Why can't she excite them anymore? Is that really her problem? Why should she be put down for that. Maybe if that other person paid closer attention, they'd see many more interesting things about her.
She is saying, if we are friends, why do you treat me harshly like you would treat a stranger with your hurtful judgements? Why can't you accept me as I am if we are friends? That's fine if that's how you want to be, but she doesn't have any time for this person.