Overprotective Parents--what?

Okay, I have to start this out saying that I have great parents. I myself am not a parent of course, but I feel like since I've had lots of interaction with parents, including my own, I should have a fair say. 
I'm the youngest in my family. I have two older sisters. My parents aren't perfect, but no parents are. I do believe, though, that my parents have been really great raising us kids. 
Maybe as the youngest I have more freedom than my older sisters, but I think my parents have it figured out. I do have quite a bit of freedom, but they also trust me a lot, with good reason. They know I'm not out committing crimes or doing drugs or getting pregnant. I feel like I'm responsible and trustworthy and I get rewarded for it. I also have good friends. 
I totally get that some kids abuse their freedom and lose that trust and parents should crack down on them.
But what I don't get is when responsible, mature kids have almost no freedom. Your kid is trustworthy and doesn't get into things he shouldn't, but you want to make all his decisions? How does that make sense? Or if you let him make his own decisions and then punish him for the choice he makes. What is this? 
I think that in most cases, teenager/parent relationships can be summed up in one phrase: the more you push them, the harder they'll pull away. You can't constantly nag your kids to make the decision you would make, or they'll go completely against you one day and do something terrible. Simply give them your knowledge and advice, then let them make their own decisions. Choices and their consequences are a part of life-a part of learning how to live. So let them make their choices and they'll have their consequences. Be it good or bad, it'll be a learning experience. Don't you want your kids to learn? 
There's my two cents on the matter..