For the most part it is natural for teenagers to rebel against their parents. It is part of the growing up process. When you are a child, you love your parents like a child. You are extremely attached to them. If you always loved your parents with this childish love, you would never leave the house and go have your own family. During the teen years, the child tests and pushes against this relationship, doing some damage to the relationship so that it can be reformed into an adult-parent relationship.
A simple example of this is that most teens at some point or other are embarrassed by their parents. When they were kids, they thought their parents were the greatest. Now, as teens, they are starting to separate themselves from their parents and establish themselves as individuals.
Now, this is no way justifies rebelling against your parents. It doesn't make it okay to break rules, be disrespectful and etc. Teens don't need to be a flat out jerk to their parents in order to reform their relationship in a new way. It seems to me that teens today are more likely to stage a huge rebellion, and I think this is mostly due to the way that they are raised. If you are spoiled and given whatever you want as a child, you are going to expect to receive what you want as a teen. Kids want toys and an extra cookie or something....teens want to stay out all night, party and etc. Parents gave the kid the extra cookie, but most of them don't want their kids doing drugs. So, they start trying to put their foot down...
The teenage years were already primed by nature to be a bit difficult and turbulent - hormones, brain development, redefining relationships - now have a totally spoiled kid goes through that. It isn't going to be pretty.
It is also an important fact that if you spoil your child, you to some extent teach your child not to care about your feelings. Any child who really cared about their parents wouldn't cry, pout, get angry or throw fits when they don't get what they want. So, when this kid hits puberty, they aren't going to magically start being considerate of their parents' feelings. They aren't going to consider their parents' feelings at all. They've been raised to believe that their parents' feelings don't matter.
You said that teens who are rebelling are hurting themselves more than others. Another side-effect of spoiling children is that they do not learn self-discipline. Self-discipline is the ability to say, "I can wait to get what I want." It is the ability to set a long term goal and work towards it, with little payoff on an immediate basis. Teens who were spoiled aren't thinking about college, they aren't thinking about their report cards. They are thinking about what they want *Right NOW*. They have never learned to wait or to put in time and effort.
Obviously, this does not apply to all teens. I didn't rebel at all against my parents. I redefined our relationship in other ways. It sounds like you aren't rebelling either. You should be very proud of yourself :). You are doing a great job working hard towards college and your future. It is so sad that your attitude isn't as common as it used to be. I hope your parents realize what a wonderful child they have :).