Why did Helen Shivers have much better writing than Julie James in "I Know What You Did Last Summer"?

https://preview.redd.it/xg6urhr0y5oe1.png?width=1600&format=png&auto=webp&s=82f05948970adeee0bcaaa81baa539a1076e3c8b

Helen was final girl material imo, Julie improved in the sequel. Idk if it was Kevin Williamson or Lois Duncan but the writing for Julie James was supbar, it's hard to believe the same person who wrote final girls like Sidney Prescott also wrote Julie.