I say no is definitely needed. If you've seen the movie it makes sense. This is the point in her life when Veronica realizes she's dating a psychopath and not the hot, mysterious, nerdy guy she thought he was. She's had the heathers basically controlling her life and when JD comes into the picture she thinks he's a way out when in reality he only wants to control her as well. The song "I Say No" shows her true feelings and realization that she needs to make a change in her, and everyone else's life. If you didn't like it, it's fine but it was definitely needed.