I don't really understand "age of consent." Like there's some particular milestone at which I suddenly am capable of consenting to things... I'm suddenly cognizant of the best presidential candidate, I can suddenly hold my liquor, I can suddenly make informed choices about the uses and dispositions of my own body. And if I were English, that milestone would naturally occur two year earlier because of... what, the climate? That doesn't really make sense, logically.
However, law and reason can't always coincide, particularly when we're speaking of something as necessarily arbitrary as legal responsibility. My parents were legally responsible for me until I was eighteen; before that, I was legally not a real person, I was an adjunct... a person-in-training, as it were, an apprentice. Now, if I were legally responsible for myself at, say, age 12, would it have made much of a difference? Well, yes, my parents could have abandoned me if they so chose without breaking the law.
So the original law was based on whether or not I was physically mature: have I reached my full strength and become capable of caring for myself? Some people hit that earlier than others. I didn't reach full physical maturity, and wasn't mentally or emotionally capable of caring for myself, until I was thirty. Some people hit that state in their teens. It's different for every person.
However, you can't judge everything on a case-by-case basis under law, or you'd have nothing but confusion. So an arbitrary line had to be drawn. In the US the arbitrary line was drawn at eighteen. And there's not much can be done about it, because the people it affects either don't have the right to participate in the political process or are labeled as pedophiles and therefore also outside of the political process.
I guess the bottom line is, the right to fuck someone of a particular age isn't that important. If it's love, you can wait (seventeen is a temporary state), and if it's not love it doesn't really make much of a difference.
This suddenly makes me think of a movie I saw once, in which an entire nation of teenagers banded together, spurred by a Jim Morrison-like rock star, and pretty much went on strike until the voting age was lowered to fifteen; then they elected the rock star as president, and all hell broke loose. It was the most delicious paranoia.