The central setting is usually in a school, and the last thing likely to happen is education. Rich teens are important teens, otherwise, you're an extra hanging around in the background like wallpaper. You date to have sex. Virginity is a plague that must be eliminated before graduation.
Sex is the major topic of all discussions, including comparison of anatomical sizes.
The seemingly nice guy that dad wants you to date turns out to be a jerk. The dark, mysterious bad dude that the heroine loves turns out to be a nice guy after all. We just had to get to know him. You're likely to get a detention for the most menial infraction, but there are rarely consequences for things like physical assault. Hollywood execs know that in four years a whole new crop of teens will ante up an hour and a half worth of part time wages to see this schlock again.